RYBP and neoplasm: To inhibit apoptosis, it encodes proteins such as the E3 ligase WSSV222, which mediates ubiquitination and degradation of a host tumor suppressor-like protein (42); AAP-1 (WSSV449), which binds and inhibits the effector caspase PmCasp (43), and other anti-apoptotic factors, including WSSV134, WSSV322, and ORF390, which suppress caspase-dependent apoptosis (44, 45).