KLF4 and seminoma: Human tissues used for positive controls demonstrated positive staining of OCT4 (Supplementary Figure 3A) and NANOG (Supplementary Figure 3B) on sections of seminoma, SOX2 (Supplementary Figure 3C) on skin, KLF4 (Supplementary Figure 3D) on breast carcinoma, and c-MYC (Supplementary Figure 3E) on colon.