Conversely, OLFM4-knockdown cells CAL27-shOLFM4 (IC50 = 1.315 μg/mL) and 5-8F-shOLFM4 (IC50 = 1.356 μg/mL) showed markedly increased cisplatin sensitivity relative to their controls (CAL27-shOLFM4-NC (IC50 = 1.623 μg/mL) and 5-8F-shOLFM4-NC (IC50 = 3.984 μg/mL)), establishing OLFM4 as a key mediator of chemoresistance in HNSCC (Figure 4F). Here, OLFM4 is linked to head and neck squamous cell carcinoma.