PAX6 and retinoblastoma: Apart from the decreased tumor cell apoptosis after the inhibition of endogenous PAX6 in the human retinoblastoma cells, we found that the inhibition of endogenous PAX6 led to an induction into the cell cycle S phase of the SO-Rb50 cell line and an induction into the cell cycle G2/M phase of the Y79 retinoblastoma cell line.