Our results are in agreement with the previous study, which suggested that, in theory, combining multiple scoring functions should always provide improved performance over individual scoring functions in simulated virtual screening experiments [32] . According to the present results, we cannot definitively conclude that more scoring functions result in a better performance. For example, application of double-scoring schemes (e.g., Surflex_S-core&D_Score) could also obtain 24 hits in the top 1% of the screening set, which is the same result obtained using the quadruple-scoring scheme. However, it is important to note that double-scoring schemes do not outperform the best individual scoring function in all cases. For example, Surflex_Score&jain could obtain only 19 hits, which is slightly less than the 20 hits obtained from the single scoring function, jain. Therefore, it is largely unpredictable which combinations of scoring functions would produce the optimal results. In practice, it is better to test all possible combinations of scoring functions on the appropriate samples.