To examine the intrinsic signaling pathways that mediated BMEC apoptosis in response to infection with the C. krusei yeast and hypha phases, the effect of caspase-3/7 inhibitor I, Z-LEHD-FMK, and Z-IETD-FMK on the C. krusei-induced BMEC apoptosis was analyzed by assessing the change incaspase-3, caspase-8, and caspase-9 proteins. The gene discussed is CASP9; the disease is infection.