Our previously published microarray data sets that interrogate differential gene expression in epithelial-like and mesenchymal-like tumor cells (10) demonstrated that epithelial-like cells have a higher expression of Cdkn1a (gene encoding p21), including comparisons of 344SQ versus 393P cells (fold change 0.57, P = 0.003) and 393P-ZEB1 versus 393P-vector (fold change 0.27, P < 0.0001). This evidence concerns the gene ZEB1 and neoplasm.