Among the many types of human cancers examined, ZEB1 was the transcription factor that most consistently and significantly showed strong positive correlation with ZAK at the mRNA level, better than other classic EMT transcription factors, such as Snail 1 (SNAI1), Snail 2 (SNAI2, Slug), Twist 1, and Twist 2 (Fig. 2b, Supplementary Figure S2b; Supplementary Table S1). This evidence concerns the gene SNAI2 and cancer.