B PIPKIγi5 specifically interacts with LAPTM4B, but not LAPTM4A or LAPTM5. Top: schematic diagram of all three LAPTM members. Bottom: each Flag‐tagged LAPTM protein was immunoprecipitated from HEK293 cells cotransfected with Myc‐tagged PIPKIγi5 and empty vector or Flag‐tagged LAPTM, and the co‐immunoprecipitatedPIPKIγi5 was examined by immunoblotting. 