ATP2A1 and syringoma: Meanwhile, we analyzed the protein expression of the four candidate genes CACNA1S, ATP2A1, RYR1, and MYLK3 by IHC staining, then focused on the differences of their expression between tumor cells of MAC, syringoma, trichoepithelioma, basal cell carcinoma-infundibulocystic type and normal sweat glands.