We observed that ISEMFs from SBS patients have reduced BMP4 mRNA expression compared with normal ISEMFs (Figure 8), and incubation of ISEMF-SBS enteroid cocultures with exogenous BMP4 reverses the SBS ISEMF-induced increase in enteroid surface area (Figure 9). This evidence concerns the gene BMP4 and macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss.