Appl1 knock-out MEFs have normal cell proliferation rate and Akt signaling under normal culture conditions. A, cell proliferation in primary wild-type, Appl1+/−, and Appl1−/− MEFs cultured in DMEM with 10% FBS. Cells were collected daily and counted. B, immunoblot analysis of Akt1/2/3 and p-Akt in the same set of MEFs at passage 1. C, Appl1 protein levels in Akt1−/−, Akt2−/−, and Akt1/2 double knock-out (DKO) MEFs.