SMO and neoplasm: The HH pathway was also altered via paracrine ligand-dependent alteration that stroma cells provoke tumour cells via IL6, VEGF, IGF, and WNT alteration, resulting in HH alteration via PTCH1 and SMO, as well as reverse-paracrine ligand-dependent alteration via stroma cells, inducing tumour cell via PTCH1 [46,47,48].