NTF4 and breast carcinoma: To further assess the specificity of binding of the NT4 peptide to HSPG in HT-29 colon adenocarcinoma, PANC-1 pancreas adenocarcinoma, and MDA-MB-231 and MCF-7 breast cancer human cell lines, we first treated the cells with the heparinase I/III blend that removes HS from proteoglycans.