Kidneys from Tsc1∆/∆ mice also exhibited multiple cystadenomas (Figure 1D,E) and increased immunostaining of phosphorylated ribosomal protein S6 (pS6) compared to Tsc1+/+ mice (Figure 1E,F), consistent with constitutive mTOR activation following Tsc1 deletion. This evidence concerns the gene RPS6 and cystadenoma.