In the last decade, the advent of immunotherapy in oncology has led to the routine use of some anti-cancer treatments, specifically immune checkpoint inhibitors (ICIs), such as the anti-PD-1/anti-PDL-1/anti-CTLA-4 antibodies, which significantly improved the prognosis and recovery rates in patients suffering from melanoma, as well as lung and kidney cancers; although, among the others, currently there are still no data concerning their possible role in compromising fertility [22]. The gene discussed is CTLA4; the disease is cancer.