The tumor suppressors Ink4c and p53 collaborate independently with Patched to suppress medulloblastoma formation

The genetic alternations in human medulloblastoma (MB) include mutations in the Sonic hedgehog (SHH) signaling pathway and TP53 inactivation. Studies revealed that in tumor cells purified from double heterozygotes, Ptc1 allele, but not Ink4c was inactivated and hence it was concluded that Ink4c combined with Ptc1 mutation is haploinsufficient for tumor suppression.