Gene expression analysis. (A) Expression profiling data were converted into a heatmap using CLUSTER and TREEVIEW software (red indicates high; green, low; black, medium expression level). Data show homeobox genes differentially expressed in HL and NHL cell lines. Genes showing significant up-regulation/down-regulation in HL (HOXC6, SHOX2, HOXB8, HOXB9, HOXB4, SATB1, HOP/PAX5, POU2F2), shown in red/green, respectively, were subsequently analyzed by RT-PCR, depicted in panel B together with HLXB9, genes located within the HOXB cluster (HOXB13, PRAC, PRAC2, mir-196a1) and involved in HOXB9 transcription (FGF2). Expression of upstream binding factor (UBF) was used as positive control for cDNA quality. NTC indicates no template control.