ARID1B and neoplasm: Although loss of core SWI/SNF protein expression is not yet a required criteria for the diagnosis of DDC/UDC in the World Health Organization (WHO) Classification of Tumours, adding ARID1B to SMARCA4 and SMARCB1 is very helpful in the diagnosis of a significant number of cases; cases for which the pathologist may have otherwise had to use a nonspecific diagnostic terminology [32].