PTGER4 expression in the SHH subgroup was increased in comparison to its expression in Group 3 and Group 4 tumors (t-probabilities = 1.6e-6, 2.7e-8, respectively), but not WNT tumors, in the Toronto series of medulloblastoma patients (Figure 3f) [10]. This evidence concerns the gene SHH and medulloblastoma.