RYR1 and syringoma: We demonstrated that the protein expression of CACNA1S, RYR1, ATP2A1, and MYLK3 was obviously upregulated in MAC tumor cells compared with normal sweat glands and syringoma tumor cells, while was basically negative in trichoepithelioma and basal cell carcinoma, infundibulocystic type (Fig. 3), except one case of trichoepithelioma showed partial RYR-1 week positive (+) (Table 3).