Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12976-017-0071-8/MediaObjects/12976_2017_71_Fig1_HTML.gif)
Compartmental scheme for proliferation and differentiation of the small intestinal epithelium, based (with permission) on Figure 7 of ref. 30. Subscripted k’s represent differentiation rates; unscripted lowercase Greek letters (α, β, γ, δ, ζ) indicate proliferation rates; subscripted λ’s indicate cell loss rates. Colors match the scheme in Figure 7 of ref. 26. CBC: crypt based columnar cell; TAC: transit amplifying cell; AP: absorptive progenitor; EC: enterocyte; SP: secretory progenitor; EEC: enteroendocrine cell; TC: Tuft cell; GPP: goblet / Paneth progenitor; GC: goblet cell; PC: Paneth cell