The percentage of viable cells further decreased after 72 h incubation with IFNβ, ranging between 40 and 70% at a concentration of 1,000 U/ml in the five sensitive NPC cell lines and C17-PDX cells (HONE-1, HK1, TW01, C17-PDX: p < 0.001; HONE-1 EBV, CNE-2: p < 0.01). Here, IFNB1 is linked to nasopharyngeal carcinoma.