I Top: GSTpull‐down assay of LAPTM4B N‐terminus and PIPKIγi5 C‐terminus with increased concentration of PtdIns(4,5) P2 addition. Bottom: Quantification of the relative amounts of PIPKIγi5 C‐terminus bound to LAPTM4B N‐terminus in top panel (mean ± SD; n = 4). 