Ectopic RBPMS2 expression in differentiated digestive SMCs hinders their ability to contract and induces their proliferation leading to their dedifferentiation, demonstrating that RBPMS2 expression has to be tightly regulated to avoid SMC dedifferentiation, as observed in chronic intestinal pseudo-obstruction syndrome (CIPO) and gastro-intestinal stromal tumors (GISTs) (9,11). Here, RBPMS2 is linked to chronic intestinal pseudoobstruction.