Intriguingly, we found that 12 (PLK1, CDC7, AURKB, CDK1, PBK, CHK1, MELK, BUB1B, PLK4, VRK1, TTK, MASTL) out of these 17 commonly reduced kinases (Fig. 2b and Supplementary Table S3) are part of a kinase signature that distinguishes LumA BC from basal BC30. This evidence concerns the gene CHEK1 and breast cancer.