Thus, GADD34 heterozygous mutation noticeably increased the incidence of medulloblastoma in Ptch1+/− mice (29 out of 68 Ptch1+/−; GADD34+/− mice vs 23 out of 76 Ptch1+/−; GADD34+/+ mice, Figure 2B). Here, PTCH1 is linked to medulloblastoma.