TSPAN4 and neoplasm: In orthotopic allografts, ITM2B1‐115 overexpression in Renca cells notably promoted tumor growth, accompanied by increased Ki67 expression, whereas the knockdown of TSPAN4 in Renca cells to inhibit migrasome formation blocked the protumoral function of ITM2B1‐115, with decreased Ki67 expression levels (Figure 4H,I).