Knockdown of APPL1/2 with siRNA resulted in reduced cell numbers when compared with PC-3U control cells treated with EGF only (Figure S5c), suggesting that APPL proteins are important for proliferation or survival of EGF-stimulated cells, consistent with the observation of increased APPL1 gene expression and protein expression during the initiation and progression of prostate cancer.16 Here, APPL1 is linked to prostate carcinoma.