GSK3B and pheochromocytoma: In glioma cells (H4) and in phaeochromocytoma-differentiated neurons (PC12), GSK3b inhibition using lithium chloride (LiCl) causes an increase in expression of PGC-1a1 and PGC-1a4 isoforms (Martin et al., 2018), but neither cell type expresses the B1E2 isoform which is the dominant form of PGC-1a in primary neurons.