CDKN1A and cancer: CBD was recently found to increase protein expression of ATM and p21, but not p53 in an in vitro model of gastric cancer, suggesting CBD promotes cell cycle arrest at the G0–G1 phase.68 Our data suggest that CBDV acts in a similar manner; however, it is important to emphasize that p21 has roles in both enhancing and inhibiting apoptosis depending on the type of stressor; thus, generating this response in a cancer cell model will be different to responses of astrocytes subjected to OGD.