The function of Ensembl gene identifier ENSG00000243725 (TTC4, tetratricopeptide repeat domain 4) is as follows. Co-chaperone that recruits molecular chaperones Hsp90 (HSC82 and HSP82) and Hsp70 (SSA1) to nascent polypeptides, facilitating their proper folding into functional proteins (PubMed:18320024). Client proteins include eukaryotic elongation factor eEF2, a key player in cellular translation. Stimulates SSA1 ATPase activity, but not Hsp90 ATPase activity (By similarity). Promotes Sendai virus (SeV)-induced host cell innate immune responses (PubMed:29251827). {ECO:0000250|UniProtKB:P33313, ECO:0000269|PubMed:18320024, ECO:0000269|PubMed:29251827}.