P2RX7 and myeloid sarcoma: Several cohort studies have acknowledged an association of loss-of-function, minor allele frequency P2X7 receptor SNP, rs28360457, coding for R307G with protection against MS and a gain-of-function haplotype rs208294, coding for H155T, which increases risk of MS (Oyanguren-Desez et al., 2011; Gu et al., 2015).