CD74 and cyst: Knockout of CD74 decreased cyst index (Figure 1B), kidney weight to body weight ratios (KW/BW) (Figure 1C) and blood urea nitrogen (BUN) (Figure 1D) in Pkd1flox/flox:Ksp-Cre:CD74−/− mice compared to those from Pkd1flox/flox:Ksp-Cre:CD74+/+ mice.