IFNA1 and neoplasm: However, there was no significant difference in the tumor weight and MVD between groups C and D when IFN-α treatment was discontinued for 20 days (1.93 ± 0.58 g vs. 1.54 ± 0.49 g, P = 0.233; 59, 95% CI = 43–73 vs. 51, 95% CI = 38–64, P = 0.369, respectively).