For instance, in the SJDAWN phase 1 clinical trial (NCT03434262) both group 3 and group 4 tumors belong to the same arm receiving ribociclib combined with gemcitabine although the efficacy of CDK4/6 inhibitors has only been proven in preclinical models of group 3 medulloblastoma. Here, CDK4 is linked to medulloblastoma.