CASP3 and colorectal cancer: Previous studies show that Polyphyllin G arrested A549 and NCI-H1299 cells in the G2/M phase [28]; Li et al point that Polyphyllin G could induce cell apoptosis, together with cell cycle arrest in G1 phase, and trigger apoptosis in a caspase-3-dependent manner in human colorectal cancer cells (HT-29 and SW-620) [42].