Techniques are provided for detecting and correcting polarity reversals in signals generated by readwrite heads that are used to read magnetic data. An error of the estimated cylinder-intake-air amount is calculated by comparing the reference cylinder-intake-air amount with an estimated cylinder-intake-air amount base value. The present invention discloses methods for identifying, diagnosing, and predicting survival in a lymphoma or lymphoproliferative disorder on the basis of gene expression patterns.