Gender prediction based on expression of the Y-chromosome specific gene <i>RPS4Y1</i>.

<p>The log2 transformed values of <i>RPS4Y1</i> expression level are clearly separated between male and female samples both in CTRL and patients with COPD (>10 in male samples and <10 in female samples). There were no gender mismatched samples in the CTRL and 5 mismatched samples (2 in females and 3 in males) in the COPD set (error rate of 1.5%).