ARID1B and cancer: We however believe that these additional mechanism(s), if present, would only be involved in rare cases of DDEC/UEC, based on our prior studies that genetically screened 43 DDEC for mutations in all SWI/SNF complex proteins (implicated in human cancer development) which identified only genomic inactivation of SMARCA4, ARID1B, and SMARCB1 as recurrent events [2, 11].