Introduction . The tumor microenvironment (TME) consists of a variety of resident or infiltrating host cells (e.g., malignant cells, immune cells, and stromal cells) and non-cellular components (e.g., secreted factors, extracellular matrix proteins), all of which have important effects on tumorigenesis, progression, and metastasis1 , 2 , 3 , 4and are associated with response to immune checkpoint blockade (ICB) therapy3 , 5 , 6 , 7 , 8. However, the TME varies gr...