POSTN and neoplasm: Regarding tumor ECs, one study identified two populations, IGFBP3+ ECs and SPRY1+ ECs (27), another study defined IGFBP7+PLVAP+ as tumor ECs, with high expression of HSPG2 and POSTN, which are associated with angiogenesis (19), and another study suggested that tumor ECs highly express insulin receptor (INSR) and HSPG2.