Molecular model of the drug Calpeptin (C20.H30.N2.O5). Calpeptin is a rho kinase activator and an inhibitor of calpains, a family of calcium-dependent cysteine proteases involved in apoptosis, long-term potentiation in neurons, and cell cycle progression. It has been shown that Calpeptin also acts as an inhibitor to the main SARS-CoV-2 protease. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue) and oxygen (red).