We discovered that the CAR fused with an IDR from FUS, EWS or TAF15 promoted the formation of CAR-T conjugation with cancer targets, the mechanical strength of CAR-T synapses and membrane-proximal signaling, which led to an increased release of cytotoxic factors and a higher killing activity toward low-antigen-expressing cancer cells in vitro. This evidence concerns the gene EWSR1 and cancer.