SMARCA4 and cancer: However, the loss of ATPase subunits does not necessarily eliminate all SWI/SNF functions, as seen in cancers such as small cell carcinoma of the ovary—hypercalcemic type (SCCOHT)—where there is a dual loss of SMARCA4/2, but which retain residual complexes without the catalytic activity that may contribute to oncogenic gene expression [196].