Schematic of phosphosites identified in high-throughput studies on 24 transmembrane segment ion channel α subunits. Areas of the green circles represent the percentage of phosphosites found within a specific cytoplasmic domain (N-terminal, ID I-II, ID-II-III, or C-terminal). Numbers adjacent to circles represent the total number of unique phosphosites identified within that domain for all members of that family (Cav: six members; Nav: four members).