GSK3B and medullary thyroid gland carcinoma: Accordingly, GSK3β inhibition has already shown anti-tumor potential with anti-proliferative and pro-apoptotic effects in neuroblastoma, BON-1, H727 and medullary thyroid carcinoma cells being accompanied by reduced expression of β-catenin and neuroendocrine tumor markers [70, 71, 76, 77].