Performance comparison of PS-HomPPI and NPS-HomPPI. Only proteins for which predictions could be generated by both PS-HomPPI and NPS-HomPPI (139 out of 270 chains from Trans135) were used in this evaluation. The lower (Q1), middle (Q2) and upper (Q3) quartiles of each box are 25th, 50th and 75th percentile. Interquartile range IQR is Q3-Q1. Any data value that lies more than 1.5 × IQR lower than the first quartile or 1.5 × IQR higher than the third quartile is considered an outlier, which is labelled with a red cross. The whiskers extend to the largest and smallest value that is not an outlier. Averages are marked by green dots.