Gene profiling of a lesion responding to treatment. (a) Computer tomographic imagesof two lesions in the same patient (M.F.) before starting treatment (7 March, 2001) and at follow-up administration. The FNAs were obtained after the 7 March images and before the following ones. (b) Genes differentially expressed following the fourth IL-2 dose in M.F. compared to the rest of the FNAwere selected using a two-tail t-test, with unequal variance (p2 < 0.05). In this fashion, 102 genes were identified whose expression was specifically altered in the responding lesion. Only 19 of these are shown in the clusterogram. Red represents upregulation in test samples compared with the pre-IL-2 administration reference sample, and green the opposite. Gene identity is shown on the right. *Genes upregulated in acute rejection of kidney transplant (PBMC and renal biopsy tissue, ); **genes with similar expression in NK cells exposed to IL-2. Similarly, 68 genes were found to be differentially expressed between the first IL-2 treatment in M.F. and the rest of the FNA (small image on left).