Semiquantitative PCR of 6 genes in primary ATL cells and control CD4⁺ T cells. Expression of up-regulated genes in the ATL cells was detected by DNA microarray analysis and confirmed by semiquantitative RT-PCR. cDNA prepared from total RNA of 8 primary ATL cells and 5 CD4⁺ T cells was amplified by PCR with the specific primer sets listed in “Patients, materials, and methods.” The expression of HTLV-1 Tax and IL2RA was also determined by RT-PCR. The expression level of β-actin is shown at the bottom of the figure as a control.