ERBB2 and breast cancer: As shown in Table 1, analog 1 (2‐(4‐methylphenyl)‐1,2‐benzisothiazol‐3(2H)‐one) and analog 2 (2‐(4‐chlorophenyl)‐1,2‐benzisothiazol‐3(2H)‐one) both competed with HER2/FERM interaction, inhibited HER2 activation in HER2+ breast cancer cells and reduced the anchorage‐dependent and ‐independent proliferation of HER2+ breast cancer cells, although less efficiently than ebselen oxide.