CDKN2A and neoplasm: In addition, prior experiments have shown that even in vitro, DNMT inhibitor-induced p16 protein expression in tumor cells occurs only after a 24–48-h lag period following treatment [40], and our EJ6 cell culture data show that appreciable upregulation of p16 protein expression (detected by Western blot) occurs beginning at 2 weeks after a single application of FdCyd + THU (Supplementary Figure S1a).