We analyzed the ability of CTLs to kill tumor cells in vivo using a series of parameters, including the accumulated contact time of CTLs with tumor cells, the number of tumor cells killed by CTLs every day, tumor cells early-stage response time to CTL (calcium signaling), and the effector stage time of tumor apoptosis (caspase-3 activity signaling). The gene discussed is CASP3; the disease is neoplasm.