ABCB4 and medulloblastoma: The biological significance of ABC transporters expanded when the study on medulloblastoma showed the specificity of expression levels of different family members of ABC transporters, and that in SHH medulloblastoma, ABCA8 and ABCB4 levels were higher, while ABCC8 levels were lowest in the SHH subgroup [140], which may be due to the different origins of CSCs in different medulloblastoma subgroups.