In NSCLC, reduced miRNA-145 boosts EGFR, promoting cell growth and erlotinib resistance.710 Conversely, miR-145 inhibits platelet-derived growth factor receptor, decreasing proliferation and increasing erlotinib and gefitinib sensitivity.711 In breast cancer, miR-335-5p and miR-335-3p work in tandem to suppress estrogen receptor α, thereby heightening tamoxifen resistance.712 miRNAs influence therapy sensitivity by regulating processes like apoptosis, cell cycle, and EMT. Here, ESR1 is linked to breast cancer.