PDXK and neoplasm: When PD-L1 expression was evaluated within tumor cells or fibroblasts with or without material transfer or crosstalk (as indicated by PKH dyes), an increase in the percentage of PD-L1+ cells was observed in the PKH26+PKH67+ cell population in both models, compared to cells without material transfer (PKH26+PKH67- or PKH26-PKH67+, Figure 3D); the proportion of PKH26+PKH67+PD-L1+ cells in the A549 model was significantly higher compared to the H358 model.