In addition, the level of the transcript of immunoglobulin J polypeptide (Igj), which encodes the J chain protein of IgM and IgA antibodies, in the liver of M. fortis at 2 weeks post-infection was found to be higher than that in the liver of C57BL/6 mice (Hu et al., 2017), which indicated increased production of IgM and IgA. Here, CD40LG is linked to infection.