The Msc (musculin) is responsible in vitro for the low responsiveness of human Th17 cells to the growth factor IL-2, providing an explanation for Th17 cells rarity in inflammatory tissue. Through this analysis, it has been evaluated the shift in microbiota composition caused by the knock-out of the Msc gene in two diffent mice models (wild-type and DSS-induced colitis) Overall design: Total DNA was extracted from the stool of the mice, amplified to collect amplicons of variable V3–V4 regions (primers 341F and 805R) of the bacterial 16s rRNA gene and sequenced with MiSeq (2x300bp) Illumina platform.