Studies show that RA increases the expression of transglutaminase 2 (TG2), as seen in different cell types: neuroblastoma cells [11], glial cells [12], macrophages [13], rat hepatocytes [14], and human hepatocarcinoma cells, where it has been implicated in contributing to chemoresistance during chemotherapy [15]. This evidence concerns the gene TGM2 and neuroblastoma.