Fig. 6From: The canonical TGF-β/Smad signalling pathway is involved in PD-L1-induced primary resistance to EGFR-TKIs in EGFR-mutant non-small-cell lung cancerKnockdown of PD-L1 inhibits cell migration and invasion in vivo. Surgically resected lung tissues were fixed in Bouin’s fluid, and representative images of micrometastases detected by H&E staining are presented; red arrowheads indicate micrometastasesBack to article page