NEDD4L and colitis: Furthermore, mice with global deficiency of Nedd4l (Nedd4l–/–, KO) exhibited a more severe colitis phenotype when treated with a very low dosage of DSS (1%); however, it was hard to induce an obvious colitis phenotype in Nedd4l+/– and Nedd4l+/+ mice, suggesting that Nedd4l KO increased the susceptibility of mice to low-dose DSS exposure (Supplemental Figure 2, A–E).