CD4 and hyperplastic polyp: Great attention has been placed on the pathogenesis of MP immunology, especially the role of cellular immune mechanisms in the pathogenesis of severe MP.13,14 In the cellular immune response, CD4+ represents the helper induced T cell subsets, and its increase indicates the increase of immune globulin produced by B cells and the enhancement of cellular immunity; CD8+ is an inhibitory cell/cytotoxic cell subgroup, and its increase indicates immunosuppression; CD4+ and CD8+ are inter-conditioned.