“..Recent reports have shown that apoptosis contributes to the hair cycle of regrowth and loss. It is now firmly established that apoptosis is regulated by an intracellular proteolytic cascade, primarily mediated by members of the caspase family of cysteine proteases, which cleave one another and various key intracellular target proteins to destroy the cell. Two prototypical signalling pathways for the induction of apoptosis have been described. One pathway involves ligation of death receptors that activate procaspase 8 and possibly other initiator caspases. The other pathway is controlled by the mitochondrion and involves the apoptosis protease inducing factor-1. Once activated by cytochrome c,, together with cofactor nucleotide triphosphates, they then bind and activate procaspase 9, which in turn cleaves and activates caspase 3 and other downstream caspases. Therefore, caspase 8 and 9 represent the pinnical caspases in the death receptors and cytochrome c/Apap-1 pathways respectively….”