Because GM-CSF has been considered to shift macrophages into an M1-like phenotype,36 Ly6Chi monocytes depend on M-CSF signaling for their recruitment and extravasation to tumors.37 These studies and our data suggest that the maturation status of i.t. DCs rather than the number of immature DCs infiltrating the tumor is a critical factor involved in triggering antigen-specific T cell responses. This evidence concerns the gene CSF1 and neoplasm.