The statistical errors of correlation coefficient and RMSE were estimated using 1000 rounds of the bootstrapping method. The intermolecular sidechain contact (SC) between the ligand to the residual neuraminidase was counted when the spacing between non-hydrogen atoms of them is ≤4.5 Å. The intermolecular hydrogen bond (HB) between the residual neuraminidase and ligand was counted when the angle ∠ between acceptor-hydrogen-donor is ≥135 0 and the distance between acceptor and donor is ≤3.5 Å.