The presence of IGF-IR in the tumour specimens from patients with AIDS-KS coupled with the essential functional role of the IGF-IR in KSIMM biology determined us to investigate the effect of PPP, a new, specific IGF-IR tyrosine kinase inhibitor, which has been shown to have antitumoral proprieties in vivo (Girnita et al, 2004). This evidence concerns the gene IGF1R and Kaposi's sarcoma.