A quinazoline derivative that exhibits immunosuppressive effects by selectively inhibiting JAK3 (IC50 = 1.8 μM versus IC50s > 10 μM for JAK1 and JAK2); also inhibits EGFR (IC50 = 4 nM) and VEGFR as well as the non-receptor tyrosine kinases, Abl, Lck, and Src.