Since ISG15 modifies proteins through a process called ISGylation [17], which involves three cascade enzymes: An E1 enzyme (UBE1L), an E2 enzyme (UbcH8), and one of several E3 ligases to catalyze ISG15 conjugation of a specific protein, we hypothesized that increased ISGylation of proteins targeted by ISG15 in cells may mediate the suppressor effect of ISG15 in ovarian cancer progression. Here, ISG15 is linked to ovarian carcinoma.