Strong MUC6 staining was linked to advanced pT stage (p = 0.0464), defective MMR status, and right‐sided tumor location (p < 0.0001 each) in colorectal cancer, as well as to high tumor grade (p = 0.0291), nodal metastasis (p = 0.0485), HER2 positivity (p < 0.0001) and a negative ER (p = 0.0332)/PR (p = 0.0257) status in breast carcinomas of no special type. Here, ESR1 is linked to colorectal cancer.