CST4 and colitis: Current studies have identified various protein components in Ts-AES with potential regulatory functions, e.g. serine protease from adult stage of T. spiralis alleviates the severity of TNBS-induced colitis by balancing CD4+ T cell immune response [73]; recombinant T. spiralis cystatin alleviates polymicrobial sepsis through activating regulatory macrophages [58].