SMARCA1 and neoplasm: Thirdly, considering the differences in the methylation profiles observed between SMARCB1- and SMARCA4-deficient neoplasms, the dysregulation of the PRC2 complex subsequent to the loss of inhibition by the SWI/SNF (SMARCB1- or SMARCA4 loss) does not appear to account solely for the epigenetic acceleration observed in EpS.