MKI67 and nasopharyngeal carcinoma: However, there was a significant effect of time, with NPC proliferation significantly higher in the 24 vs. 6 h exposure for both EdU incorporation (F (1, 12) = 23, p = 0.0005, η2 = 0.65) and Ki-67 immunoreactivity (F (1, 12) = 130, p < 0.0001, η2 = 0.90).