Expression of CMT2b Rab7 mutants caused decreased neurite outgrowth in neuroblastoma cells, which could be reversed by treatment with valproic acid, an activator of extracellular signal-regulated kinase (ERK) and c-Jun terminal kinase (JNK) signaling pathways, both of the mitogen activated protein kinase (MAPK) superfamily [17, 18], suggesting this signaling pathway plays a role in the disease mechanism. Here, RAB7A is linked to neuroblastoma.