The aim of this study was to analyze the clinical characteristics of patients taking Factor Xa inhibitors (FXai), either oral direct FXai (i.e., apixaban, edoxaban, or rivaroxaban) or enoxaparin (only in active cancer patients) both overall and as individual groups, as well as to estimate the incidence of and risk factors associated with major bleeding during FXai use. The gene discussed is F10; the disease is cancer.