Identification of a genomic classifier for induction failure among 50 T-ALL samples. PAM cross-validation was used to identify genes that could distinguish patients who failed induction (⋯) from those who maintained a CCR for more than 4 years (—) and from those who relapsed after achieving remission (- -). A centroid level of 0 corresponds to 54 675 genes, ESTs, and probe sets, while a centroid level of 4.95 corresponds to 1 gene; the vertical bars indicate near-stable CV error rates between shrunken centroid threshold Δ values of 3.00 to 4.00. Asterisk indicates most efficient classifier.