This subfamily contains the MIX (Marker for type sIX effectors) II clan (MIX II) domain. MIX is a marker of type VI secretion system (T6SS) effectors carrying polymorphic C-terminal toxins. Predicted activity of the C-terminal toxin domains of Vibrionaceae MIX II effectors is mainly pore-forming. Notably, many toxins identified as T6SS effectors do not contain a recognizable delivery domain or signal, suggesting that additional delivery domains may exist. Also, some of these MIX II effectors also contain N-terminal domains such as the T6SS-secreted tail component PAAR.