GPC1 and metastatic neoplasm: However, very few transcriptional changes were detected: in isoforms 4 and 6 in metastatic tumors, where, moreover, these alterations were markedly different from those observed in ascending tumors, where there is a great underexpression of glypican 1 in all types of tumors; and in isoforms − 3 and − 6 in non-metastatic tumors [21].