SP4 and urinary bladder cancer: In contrast, EV samples derived from both GCB‐sensitive and GCB‐resistant bladder cancer cell lines, including SP3 (T24 EVs), SP4 (T24GCB EVs), SP5 (5637 EVs) and SP6 (5637GCB EVs), showed no detectable GCB signal (Figure S1B,C and E).