Fusion genes involving tumor suppressor genes as fused partners that have been identified in the breast cancer samples are as follows: TSC2-TMEM204, ARID1A-THBS3, ARID1A-YTHDF2, AXIN1-ITFG3, AXIN1-ITCH, AXIN1-IFT140, CASP8-ALS2CR12, CDH1-CCDC132, CDH1-NPFFR2, CDH1-DEXI, CCDC132-CDH1, ASXL1-TM9SF4, ASXL1-PDRG1 (Tumor suppressor genes are underlined in the names of fusion genes for clarity) (Table 1). The gene discussed is ARID1A; the disease is breast cancer.