Thus, an IL-33-regulated ILC2/IL-9 immune circuit resident in the GI tract establishes a mechanistic pathway for the development of PCM which may have pathophysiological relevance for the emergence of this phenomenon arising in GI intrinsic diseases such as colorectal cancer and inflammatory bowel diseases, although this will require further study to validate this premise. This evidence concerns the gene IL9 and paracoccidioidomycosis.