Furthermore, a recent study identified Myl9 as highly important for skeletal muscle development [53] as well as to bladder and gastrointestinal smooth muscle contraction, with homozygous deletion leading to megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), a severe disease characterized by functional obstruction in the urinary and gastrointestinal tract [52,54]. This evidence concerns the gene MYL9 and megacystis-microcolon-intestinal hypoperistalsis syndrome 1.