Before revision:  We  find that both BirgRank and AptRank outperform the previous methods, especially when only 10\% of the data are given for training.
After revision:  We design three validation strategies: missing function prediction, de novo function prediction, and guided function prediction to comprehensively evaluate all six methods. We find that both BirgRank and AptRank outperform the previous methods, especially when only 10\% of the data are given for training.