Inhibition of Hh signaling through overexpression of PTCH1 or PTCH2 induces an increase in the level of autophagic activity [106], while the Shh ligand has recently been proposed as a general positive metabolic regulator in cancer [109]: indeed, studies indicate that Shh-mediated activation of autophagy could influence cancer cell survival, thus becoming a new therapeutic target [110]. Here, PTCH1 is linked to cancer.