PRDM8 and myeloid sarcoma: Second, in a series of analyses focused on MS, we identified not only the cis effects of individual MS susceptibility loci but also robust evidence for trans effects: (a) the MS locus near TBX6 on chromosome 16 influences methylation of a CpG island in the PRDM8 gene on chromosome 4, and (b) the MHC polygenic score affects methylation of an enhancer of PRKCA on chromosome 17.