PTCH1 and basal cell carcinoma: Along this line, it is then interesting to consider our results in the light of the recent results of the phase II clinical trials on the Smo antagonist GDC-0449 in colorectal and ovarian cancer: while GDC-0449 clearly demonstrated a benefit in basal cell carcinoma and medullobastoma in which activating mutations of the Ptc–Smo–Gli pathway were shown [46], this drug had no effect on colorectal and ovarian cancer even though a large fraction of the patients included had tumors with SHH expression.