What proteins start with the letter c?

Proteins that start with the letter "C" include collagen, a key structural protein found in connective tissues; casein, a major protein in milk; and cytochrome c, involved in the electron transport chain in cellular respiration. Other examples are creatine kinase, which plays a role in energy metabolism, and calmodulin, a calcium-binding messenger protein. Each of these proteins has distinct functions essential for various biological processes.