SPARC and cancer: Hypothesizing that marker genes, congruently expressed in angiogenic ECs of different cancer types, represent more universal candidate AAT targets than tumor type-specific angiogenic EC markers, we observed that several congruent genes in angiogenic ECs are involved in ECM remodeling (COL4A1, COL4A2, HSPG2, MMP2, SPARC; Fig. 2c), as previously suggested in tumor angiogenesis14,19.