Expression of housekeeping genes, GAPDH and Actin, was initially examined in single side- and non-side population cells isolated from the CWR-R1 prostate cancer cell line (Table 2) to optimize the conditions for one-step RT-PCR and also to test the reproducibility and accuracy of the entire procedure from cell collection, cell lysis, and gene expression detection. The gene discussed is GAPDH; the disease is prostate cancer.