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Adaptive immune system. Cells Innate immunity Complement protein, Anatomical division diagram with lymphoid cell, medical vector illustration. Immunity infection organism, adaptation microscopic
Antigen-bound IgM activates the C1 complex: antigen(magenta)-bound immunoglobulin M (IgM, light blue) activates the C1 complex (violet). Source: PDB entries 7k0c, 1cgd, 5hkj, 6f1c. 3d illustration
Asian smart woman present work and got praise and complement from team colleague. People applaud hands with happy smile congratulation in meeting room. Business finance, communication planning concept
Businessman holding two blank white puzzle pieces in his hands conceptual of solving a problem, growth and development.
complement activation for bacterial infection

Free stock photoscomplemental (21)

Puzzle pieces together isolated over a white background on 3D illustrationImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/puzzle-pieces-together-isolated-white-background-42379675">Image used under license from Freestock.com</a>
Doorhandle and its reflection on glass office door, with retention pond in backgroundImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/doorhandle-reflection-glass-office-door-retention-951699">Image used under license from Freestock.com</a>
Puzzle pieces together isolated over a white background on 3D illustrationImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/puzzle-pieces-together-isolated-white-background-42379678">Image used under license from Freestock.com</a>
Doorhandle and its reflection on glass office door, with retention pond in backgroundImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/doorhandle-reflection-glass-office-door-retention-951698">Image used under license from Freestock.com</a>
Angled window of college buildingImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/angled-window-college-building-1050722">Image used under license from Freestock.com</a>
3D man tied with a rope assembling a puzzle - isolated over whiteImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/3d-man-tied-rope-assembling-puzzle-100497202">Image used under license from Freestock.com</a>
Single puzzle piece isolated over a white background in 3D illustrationImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/single-puzzle-piece-isolated-white-background-42378079">Image used under license from Freestock.com</a>
Single puzzle piece isolated over a white background in 3D illustrationImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/single-puzzle-piece-isolated-white-background-42379672">Image used under license from Freestock.com</a>
Single puzzle isolated over a white background in 3D illustrationImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/single-puzzle-isolated-white-background-3d-42378073">Image used under license from Freestock.com</a>
Close-up of young black woman applying cosmetic brush to her left cheekImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/closeup-young-black-woman-applying-cosmetic-2852721">Image used under license from Freestock.com</a>
Garden arrangement in springImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/garden-arrangement-spring-143080405">Image used under license from Freestock.com</a>
Complementary on chalkboardImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-chalkboard-423974272">Image used under license from Freestock.com</a>
Complementary drawn in pencilImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-drawn-pencil-431477683">Image used under license from Freestock.com</a>
Complementary wooden signboardsImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-wooden-signboards-418967197">Image used under license from Freestock.com</a>
Complementary drawn in pencilImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-drawn-pencil-393197068">Image used under license from Freestock.com</a>
Complementary grunge stampImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-grunge-stamp-430655137">Image used under license from Freestock.com</a>
Complementary realistic wood emblemImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-realistic-wood-emblem-432645793">Image used under license from Freestock.com</a>
Complementary chalkboard emblemImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-chalkboard-emblem-423142600">Image used under license from Freestock.com</a>
Complementary chalkboard emblem written on a blackboardImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-chalkboard-emblem-written-blackboard-423217210">Image used under license from Freestock.com</a>
Complementary emblem with jean textureImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-emblem-jean-texture-423198733">Image used under license from Freestock.com</a>
Complementary chalkboard emblem on black boardImage used under license from Freestock.com<a href="https://www.freestock.com/free-photos/complementary-chalkboard-emblem-black-board-421513825">Image used under license from Freestock.com</a>

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