↵2-a Co-expressed subunits were visualized immunohistochemically at the cellular level. The subunits analyzed here are α₁, α₂, α₃, α₅, α₆, β₂, β₃, γ₂, and δ (where the anti-β₂ antibody used does not distinguish between β₂ and β₃, “β_2,3” is noted). In each combination the subunits of that set not detected are not indicated. Where multiple isoforms of α or β co-occur, they are not necessarily combined in one receptor molecule; for all the subunits, the co-occurrences shown are within a cell not necessarily within a molecule, and sometimes are within a cell type. [The localizations are from Mohler et al. (1996b)].