ERBB3 and cancer: Garette et al reported that trastuzumab plus the anti‐HER2 pertuzumab or trastuzumab plus the anti‐HER3 seribantumab prevents heregulin‐driven cancer cell proliferation, whereas this efficacy was lost with excessive heregulin concentrations (>1 nmol/L).26 Dual inhibition of HER2‐HER3 interactions by different mechanisms might have the advantage of robustly preventing heregulin‐dependent HER2‐HER3‐AKT signaling.