In contrast, the mucosal chymase MCPT1, implicated in the expulsion of T. spiralis [13], was not affected by the lack of serglycin proteoglycans (Fig. 2i), suggesting that MCPT1 remains serglycin-independent during infection with T. spiralis. These findings on MC protease expression may reflect a difference in the immune response between tissues as well as in the response to different infectious agents. Here, CPT1B is linked to infection.