SNAI1 and breast cancer: Besides in breast cancer, expression levels of TWIST1 and SNAIL are also associated with poor prognosis in lung, gastrointestinal, hepatobiliary, head‐and‐neck, and urinary cancers as demonstrated in a meta‐analysis of 4938 patients in 38 studies showing poorer overall survival in those with high expression of TWIST1 or SNAIL1 (HR = 2.07 with 95% CI 1.63–2.63 and HR = 1.63 with 95% CI 1.33–1.99, respectively) (Zhang et al., 2014).