SNAI1 and breast cancer: RKIP has been reported to be a tumor suppressors in a variety of cancer types, including colorectal cancer [9, 10, 24], gastric cancer [25, 26], esophageal cancer [27], breast cancer [28], etc., and the mechanisms were mainly attributed to its involvement in the RKIP -NF-κB-Snail circuit in previous reports [13, 29, 30].