PCNA and breast cancer: The methanolic extract of this mushroom caused cell cycle arrest at the G0/G1 phase, induced the expression of p21, p53, p27, and p19, and downregulated the expression of CDK4, CDK6, Ki67, E2F transcription factor 1 (E2F1), transcription factor Dp-1 (TFDP1), and proliferating cell nuclear antigen (PCNA) genes in breast cancer MCF-7 cells.