part of adult midgut region adult midgut region R4 adult midgut region R4c 2014-06-05T17:29:32Z Subregion at the posterior end of the adult midgut region R4. It is composed of enterocytes with small apical protrusions. It can be distinguished from the anterior region R4b by gene expression. adult midgut P3 region FBbt:00110904 adult midgut posterior 3 region fly_anatomy.ontology