PDGFD and medulloblastoma: Additionally, in Set A there are at least two genes whose expression is modified, Gli1 and Pdgfd, which are markers of Shh-type medulloblastoma (Kool et al., 2008; Gibson et al., 2010; Northcott et al., 2011, 2012c; Taylor et al., 2012; Hooper et al., 2014).