Furthermore, Marchio et al (1999) reported that tyrosine phosphorylation of VEGFR-3 was increased in Kaposi sarcoma cells treated with VEGF-C recombinant protein as well as C156S mutant VEGF-C recombinant protein, a selective ligand and an activator of VEGFR-3, although devoid of any Flt-1 activation property. Here, FLT4 is linked to Kaposi's sarcoma.