The ΔNp63 isoform of p63, which is the predominant isoform expressed in mammary epithelium, maintains the multipotent stem cell population in normal epithelium as well as in breast cancer; ΔNp63 drives expression of Hh ligands, PTCH1, GLI1 and GLI2 [63]. This evidence concerns the gene GLI1 and breast carcinoma.