Choosing size of the signature. The relationship between the number of features in a prognostic signature and the specificity at 90% sensitivity of the corresponding prognostic test, evaluated by 40-fold cross-validation. We select mopt = 80, the smallest value that achieves roughly maximum specificity at the 90% sensitivity level. The specificity observed on the validation set is in fact higher.
Xu et al. BMC Bioinformatics 2008 9:125 doi:10.1186/1471-2105-9-125