FKA has been reported to inhibit cell proliferation in a dose-dependent manner by decreasing Skp2 protein post-translationally in numerous tumors(Table 2), including pRb-deficient prostate cancer cells, bladder cancer cell lines (Tang et al., 2008), HER2-overexpressing breast cancer cell lines (Jandial et al., 2017), synovial sarcoma cell lines (Wang J. et al., 2020), and osteosarcoma cell lines (Zhang et al., 2018). This evidence concerns the gene SKP2 and prostate cancer.