CD33 and neoplasm: Five clusters of PanCK positive tumor cells were identified: PanCK positive, PanCK/PD-L1 double positive, PanCK/PD-L1/CD33 triple positive, PanCK/CD33/FOXP3 triple positive, and PanCK/CD68/CD33/PD-L1/FOXP3 positive (Fig. 2a, b).