Gene expressions of neoplastic cells in xenograft HSA tumors. RT-PCR analyses of the expression of endothelial cell-specific markers (CD31 and vWF), angiogenic growth factors/receptors (VEGF-A, flt-1, flk-1, bFGF, and FGFR1), and homeobox genes (HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1) in the xenograft HSA tumors (1: Si, 2: Re, 3: Ud, 4: Sy, 5: Sa, 6: Ju, 7: normal canine spleen, 8: normal mouse spleen, and 9: negative control of RT-PCR). The mRNAs of endothelial cell-specific markers, angiogenic growth factors/receptors, and homeobox genes were detected in all the xenograft HSA tumors. In particular, the mRNAs of VEGF-A164 (177-bp) and VEGF-A188 (249-bp) were detected in all the xenograft HSA tumors, but VEGF-A182 (231-bp) was not present. The 2 variants of HoxA9 mRNA (314-bp and 141-bp bands) were detected in all the xenograft HSA tumors.