PTCH1 and neoplasm: In line with this observation, Schmid et al. demonstrated that the expression of Hh pathway-related genes varied considerably among the investigated ovarian cancer tissue samples: more than half of the tumor samples showed Hh signaling or pathway activation, either by expression of transcription factors and Hh ligands, or by overexpression of Ihh/Shh and the PTCH1/PTCH2.