GRK2 and cancer: In addition, it will be of great interest to investigate a possible role of ADRBK1 in the cross-talk between epithelial cancer cells and infiltrating immune cells in PDAC, since our TMA analyses demonstrated concordant expression in tumor and immune cells in ADRBK1-positive tissues from primary human tumors, whereas isolated expression in immune cells in the absence of positive staining of tumor cells or expression in immune cells from chronic pancreatitis tissues was never observed.