GRPR and medulloblastoma: The GRPR might also regulate the growth of neuroblastoma (Kim et al., 2002; Qiao et al., 2008; Abujamra et al., 2009), although, in contrast, we could not find a role for GRPR in regulating the in vitro growth of medulloblastoma, the most common brain cancer of childhood (Schmidt et al., 2009).