RT Journal Article SR Electronic T1 CXCL9-expressing tumor-associated macrophages: new players in the fight against cancer JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP e002045 DO 10.1136/jitc-2020-002045 VO 9 IS 2 A1 Paola Marie Marcovecchio A1 Graham Thomas A1 Shahram Salek-Ardakani YR 2021 UL http://jitc.bmj.com/content/9/2/e002045.abstract AB Tumor-associated macrophages (TAMs) are among the main contributors to immune suppression in the tumor microenvironment, however, TAM depletion strategies have yielded little clinical benefit. Here, we discuss the concept that TAMs are also key regulators of anti-PD(L)-1-mediated CD8 T cell-dependent immunity. Emerging data suggest that expression of the chemokine CXCL9 by TAMs regulates the recruitment and positioning of CXCR3-expressing stem-like CD8 T (Tstem) cells that underlie clinical responses to anti-PD(L)-1 treatment. We evaluate clinical and mechanistic studies that establish relationships between CXCL9-expressing TAMs, Tstem and antitumor immunity. Therapies that enhance anti-PD(L)-1 response rates must consider TAM CXCL9 expression. In this perspective, we discuss opportunities to enhance the frequency and function of CXCL9 expressing TAMs and draw on comparative analyzes from infectious disease models to highlight potential functions of these cells beyond Tstem recruitment.