KRT4 and brain cancer: As expected, the most interconnected gene in both luminal types compared to TNBC was ESR1 [97] (DRG; breast, liver, nasopharynx, kidney, lung, bone, endometrial, and prostate cancer), and in addition, genes KIF3B, KRT4, and NFIB (DRG; breast, lung, glandular, leukemia, bone, skin, brain cancer) were shared between these two networks.