The function of HELZ (helicase with zinc finger, Ensembl gene identifier ENSG00000198265) is as follows. ATP-dependent RNA helicase that promotes degradation of mRNAs via its association with the CCR4-NOT deadenylase complex, leading to deadenylation, decapping, and subsequent degradation of target mRNAs (PubMed:31570513). Can repress translation independently of mRNA decay in a manner dependent on both the CCR4-NOT complex and the helicase DDX6 (PubMed:31570513). Involved in promoting cell proliferation, translation initiation, and ribosomal protein S6 (RPS6) phosphorylation (PubMed:21765940). {ECO:0000269|PubMed:21765940, ECO:0000269|PubMed:31570513}.