HMMR and breast carcinoma: Indeed, immortal MDA-MB-231 breast cancer cells contain an A664 frameshift mutation (cDNA change c.1992_1993insA), and the expression of HMMR is greatly reduced in lysates from nocodazole-synchronized, G2/M phase lysates generated from MDA-MB-231 cells relative to MCF7 cells or MCF10A cells (Figure 1E).