Fig. 2

Hypothesized sex- and gender-based factors contributing to differences between females/women and males/men in the efficacy of immunotherapies. Based on the available data, we hypothesize that immunotherapies that stimulate the immune responses are more efficacious in females/women, whereas treatments that repress immune responses are more efficacious in males/men. Biologically, females generally have greater immune responses than males. We hypothesize that sex differences in immune function are caused by sex chromosomal (genetic) and sex steroidal (hormonal) differences between the sexes that differentially affect immune responses to immunotherapies. Sociocultural factors, including health-seeking behaviors, access to healthcare, and reporting of adverse events, also contribute to differences between women and men in immunotherapy adherence and reporting of adverse events. Together, both sex and gender contribute to differential efficacy of immunotherapies