The function of Ensembl gene identifier ENSG00000132465 (JCHAIN, joining chain of multimeric IgA and IgM) is as follows. Serves to link two monomer units of either IgM or IgA. In the case of IgM, the J chain-joined dimer is a nucleating unit for the IgM pentamer, and in the case of IgA it induces dimers and/or larger polymers. It also helps to bind these immunoglobulins to secretory component. .