POU5F1 and inflammatory bowel disease: Interestingly, Marlicz et al. [7] reported that cells expressing markers for MSCs, EPCs, and Oct-4 + Nanog + SSEA-4 + CXCR4 + lin-CD-45-very small embryonic-like stem cells (VSELs) are mobilized into PB in CD patients, suggesting that these cells might be important in the development and regeneration of gastrointestinal epithelium in IBD [7].