MEX3D and cancer: C. elegans MEX‐3 protein is a regulator of translation that specifies the posterior blastomere identity during early embryogenesis and contributes to the maintenance of germline totipotency, immune responses, differentiation, and cancer.8, 12, 13, 14, 15, 29 In mammals, there are four MEX‐3 proteins which are thought to play same roles with that of the C. elegans MEX‐3.15 MEX‐3C contains two KH domains and one carboxyl‐terminal Ring finger domain.