SHH and neoplasm: ATO has also been shown to increase apoptosis, reduce tumor cell growth, and decrease expression of Shh target genes in vitro and in vivo in osteosarcoma, acute promyelocytic leukemia, malignant pleural mesothelioma, malignant rhabdosarcoma, prostate, and colon cancer cell lines and xenograft models [122,123,124,125,126,127].