IFNA2 and neoplasm: In the experiment of HAK-1B tumors, a significant difference in the changes in tumor volume and tumor weight was observed between the Control mice and the mice that received 0.06, 0.6, 6 or 60 μg of PEG-IFN-α2a (P < 0.0001 by two-factor factorial ANOVA; and P < 0.001~0.02 by the Mann-Whitney U test, Figure 3A and Table 2).