RB1 and glioblastoma: Retinoblastoma (Rb), p53, MAP kinase (MAPK), P13K/Akt, JAK/STAT, sonic hedgehog (Shh), and NF-κB pathways are the most common targeted dysregulated pathways found in GBM and modulated by curcumin [28,29,30,31,32,33,34].