Out-of-Bag (OOB) vs mtryFactor for the nine microarray data sets. mtryFactor is the multiplicative factor of the default mtry (); thus, an mtryFactor of 3 means the number of genes tried at each split is 3 * ; an mtryFactor = 0 means the number of genes tried was 1; the mtryFactors examined were = {0, 0.05, 0.1, 0.17, 0.25, 0.33, 0.5, 0.75, 0.8, 1, 1.15, 1.33, 1.5, 2, 3, 4, 5, 6, 8, 10, 13}. Results shown for six different ntree = {1000, 2000, 5000, 10000, 20000, 40000}, nodesize = 1.