CDK1 and cancer: Specifically, by comparing Thr14, Tyr15 and Thr161 levels in different cancer types, it appears that CDK1 is likely to be fully active only in breast cancer tissue (BRCA in Fig. 3b), where the two inhibitory residues appear hypo-phosphorylated, whereas it seems to be inactive (with Thr14 and Tyr15 hyper-phosphorylated or Thr161 hypo-phosphorylated) in the remaining cancer types.