EGFR and neoplasm: The EGFR-mutant NCI-H1975 cells exhibited a more pronounced transcriptomic response, with 696 DEGs (223 upregulated, 473 downregulated), compared with 383 DEGs in the A549 cells (167 upregulated, 216 downregulated), as summarized in Figure 2C. These findings suggest greater sensitivity to PM2.5 exposure in genetically distinct tumour types.