Substrate Selectivity APPLies to Akt

The protein kinase Akt occupies a central position in multiple signaling pathways. Although numerous Akt substrates have been identified, less is known about the factors that regulate specific cellular responses to Akt signaling. In this issue, demonstrate that the endosomal protein Appl1 modulates Aktʹs substrate selectivity to promote cell survival during zebrafish development.