RASSF1 and breast cancer: An expression switch between RASSF1A and RASSF1C concomitant to CpG island A hypermethylation has also been observed in breast cancer, neuroblastoma, some lung cancers [24,31], esophageal squamous cell carcinoma [110], renal cell carcinoma [111], breast, thyroid, and colorectal cancers [109], but not in pancreatic ductal adenocarcinoma [84].