In addition, loss of SWI/SNF subunits, in particular of ARID1A, is of interest with regard to the development of novel therapeutic strategies [19,20,21,22,23,24,25,26,27] mostly based on synthetic lethality—i.e., affecting only those cancer cells that are characterized by functional loss of two genes leading to cell death, whereas individual alterations alone are compatible with viability [28,29]. Here, ARID1A is linked to cancer.