 Intracumeral abundance of chemikines, such as CXCL9, is an important driver of T-cell infiltration in tumours. Here the authors describe the design of a tumour-specific expression strategy to drive secretion of CXCL9 and an anti-PDL1 SCFV, PDL1, in the tumour microenvironment, promoting T-cell recruitment and anti-tumour immune response in pre-clinical cancer models. This article was offered by Yu Wang, Shikou Ndu, Yang Wang, and others.