4.2. Cell Culture

B16 cells were purchased from the Cell Bank of Chinese Academy of Sciences and were grown in RPMI 1640 medium (Thermo Fisher Scientific, Waltham, MA, USA) supplied with 10% fetal bovine serum (FBS, Thermo Fisher Scientific, Waltham, MA, USA), penicillin (100 IU/mL), and streptomycin (100 mg/mL, Gibco, Grand Island, NY, USA) at 37 °C in a thermostatic incubator (5% CO₂).