CDK4 and cancer: Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd (Tsukuba, Japan) applied various structural modifications [40] in order to discover the 2-aminothiazole compounds Va, Vb, and Vc as selective and potent inhibitors of CDK4 with IC50 values of 4.2, 34, and 9.2 nmol/L, respectively exhibiting potent antiproliferative activities against various cancer cell lines (Figure 3).