ARG1 and neoplasm: Furthermore, treatment with miR‐142‐5p‐EVs and miR‐183‐5p‐EVs increased the expression of arginase 1 (ARG‐1), a well‐known M2 marker, in the 4T1 tumours (P < 0.05, P < 0.01, respectively) (Figure S10c).