Comparison of feature stability of EWUSC, USC and SC on the multiple tumor data. The average Jaccard index is plotted against the number of relevant genes over five random runs of fourfold cross-validation using EWUSC and USC at ρ0 = 0.8 and SC. A high average Jaccard index indicates high feature stability. The EWUSC algorithm selects the most stable features. Note that the horizontal axis is shown on a log scale.