THOC1, ALY and hSPT4 expression in paired normal/tumor tissues by cDNA array. (A) A Cancer Profiling Array II (Clontech), representing cDNA pools from matched tumor and normal tissue, was hybridized with specific [32P]dCTP-labeled THOC1, ALY and hSPT4 probes, according to manufacturer's instructions. cDNA expression values were calculated by quantification of signal intensities in a FUJI FLA 3000. Gene expression in paired tumor/normal tissues from the same patient was quantified considering expression in normal tissues as one unit. Upper panel represents the ratio tumor/normal of each pair in the different types of tumors. N, normal; T, tumor. (B) Number of tumors showing upregulation (T/N > 1.5) or downregulation (T/N < 0.5) of THOC1, ALY and hSPT4 genes. The number is marked in bold in that tissues where the genes were up- or down-regulated in ≥50% of the tumors analyzed. A two-tailed paired t-test was used to determine whether the differences in cDNA levels in tumor versus normal samples were statistically significant (marked with *, for details see Additional file 3).