IL4R and breast cancer: Inhibiting cancer cell fusion and reducing the malignancy of fused cells are considered as promising strategies in cancer treatments.[5] For example, antibiotic minocycline and SB‐3CT (an MMP‐9 inhibitor) can impair TNF‐α‐mediated cell fusion between breast epithelial cells and breast cancer cells.[6, 7] Interleukin 4 receptor (IL‐4R) antibody can inhibit myoprogenitor‐rhabdomyosarcoma fusion and block tumor progression.[8] XAV‐939 can reduce the malignancy of macrophage/cancer fused cells through inhibiting Wnt/β‐catenin signaling pathway.[9]