Introduction Snail1 is a transcription factor that suppresses E-cadherin. The roles of Snail1 and E-cadherin in mesenchyme–epithelial transition (MET) are not yet clear. We explored the role of Snail1, E-cadherin and N-cadherin in fetal kidneys and compared it with Wilms’ tumor/nephroblastoma (WT), a rare mesenchymal kidney tumor, to better understand MET in organogenesis and malignancy.