RYBP and breast cancer: In accordance with the function of RYBP in cervical and prostate cancers, several studies have also demonstrated significantly decreased expression of RYBP at both the mRNA and protein levels in tumorous tissues compared with the corresponding adjacent normal tissues in patients with lung cancer, hepatocellular carcinoma (HCC) and breast cancer; this reduction was also observed in cell lines derived from these types of cancer compared with corresponding non‐tumorous cell lines 55, 62, 63, 64, 65.