PDCD1 and melanoma: A study aiming to decipher the diet–microbiome–immune system interplay in NSCLC patients receiving PD-1/PD-L1 blockade is currently ongoing (NCT04636775), whereas two interventional studies will explore the effect of fiber intake on the response of melanoma patients to immunotherapy as well as the incidence of adverse events and the quality of life of its participants (NCT04866810, NCT04645680).