Table 2. Antigenicity-associated sites of H1N1 identified using the random forest regression algorithm.

Order of variable importance	Amino acid position
1	141
2	130
3	43
4	54	127	193
5	186
6	80	271
7	71
8	36
9	190
10	194
11	163
12	128
13	187
14	189
15	125
16	121	205
17	321
18	133	191