Coukos and colleagues recently showed that CCL5hiCXCL9hi ovarian tumors are immunoreactive and responsive to immune checkpoint blockade, with tumor-derived CCL5 driving expression of CXCL9 from intratumoral immune cells, such as antigen-presenting cells, which in turn supports T-cell engraftment in the tumor (18). The gene discussed is CXCL9; the disease is neoplasm.