ARG1 and metastatic neoplasm: In agreement with our in vitro finding, administration of CFTRi significantly reduced Arg1 expression levels in MoMs (Fig. 7g), increased CD8+ T cell infiltration (Fig. 7h,i) and their activation (GzmB+CD8+; CD69+CD8+ T cells) in early metastatic tumors (Fig. 7i,j and Extended Data Fig. 8g).