RT-PCR of genes in the MS4A family shows human LAD-2 MCs express MS4A2, MS4A4A, MS4A6A and MS4A7 with apparent splice variants of MS4A4A and MS4A6A. Three HLMC examples are shown with varying expression of MS4A family members. HLMC consistently expressed MS4A2, and MS4A6A, with variable expression of MS4A3, MS4A4A, MS4A7 and MS4A14.