MRP4 and MRP5 have been detected in human astrocytes, while MRP5 has also been observed in human pyramidal neurons [46] and astrocytes [15], as well as primary cultures of rat astrocytes [123] and microglia [47,124]; nevertheless, these experiments were performed in samples from patients with epilepsy or glioma, and the expression may be tuned by the disease. This evidence concerns the gene ABCC4 and central nervous system cancer.