CDKN1A and breast cancer: A negative correlation between ASF1a and p21cip1 expression was also observed in HCC (r = -0.1198, P = 0.0206, n = 371), PCa (r = -0.2192, P < 0.0001, n = 497), GC (r = -0.2689, P < 0.0001, n = 415), and BC (r = -0.1280, P < 0.0001, n = 1093) derived from the TCGA dataset (Fig. 7d).