CYRIB and breast cancer: First, FAM49B mRNA expression levels in BC cell lines were evaluated using real-time PCR, which showed that FAM49B expression levels were significantly higher in the five BC cell lines—MDA-MB-231, MDA-MB-361, HCC1937, MCF-7, and SKBR-3—than in the non-tumorigenic breast epithelial cell line MCF-10A (p < 0.01; Fig. 3A).