MUC5AC and Constipation: Among the four factors investigated, the therapeutic effectiveness of Urd and AELP on mucin (MUC)2 and Krüppel-like factor 4 (Klf4) transcription were higher in the C3 KO than in the Lop-induced constipation models, while the effects on the decrease in mucin intensity and MUC1 transcription were greater in the Lop-induced constipation model than in the C3 KO model (Figure 5 and Table 5).