. "\"A series of molecular signals in which an intracellular signal is conveyed to trigger the apoptotic death of a cell. The pathway is induced by the cell cycle regulator phosphoprotein p53, or an equivalent protein, and ends when the execution phase of apoptosis is triggered.\" [GOC:mah, GOC:mtg_apoptosis]" . . "intrinsic apoptotic signaling pathway by p53 class mediator" . "intrinsic apoptotic signaling pathway by signal transduction by p53 class mediator" . . . "signal transduction by p53 class mediator resulting in induction of apoptosis" .