Please use this link to access this publication: https://www.sciencedirect.com/science/article/abs/pii/S0959804922017671 Abstract Background The use of medical cannabis has rapidly increased among cancer patients worldwide. Cannabis is often administered concomitantly with cancer medications, including immune checkpoint inhibitors (ICIs). As the cannabinoid receptors are abundantly expressed and modulate immune cells, it has been hypothesised that cannabis may attenuate the activity of ICIs. We aimed to assess the effect of cannabis on ICIs' efficiency in patients having non-small cell lung cancer (NSCLC). Method The murine model of CT26 tumour-bearing mice treated with an anti-PD-1 antibody and Δ9-tetrahydrocannabinol (THC) was used to evaluate the interaction between THC and ICIs in vivo. Correlation between use of medical cannabis and clinical outcome was evaluated in a cohort...