C-terminals of amino acid sequences that are homological to fibrinogen chains, together belong to family of FRED domains. FRED domains are engaged in protein protein interactions, like in fibrinogen and angiopoietins or bind carbohydrate, like in mammal ficolins. FRED domain spread between mentioned proteins by gen duplications and exon shuffling during evolution of multicellular animals. There are 24 genes in human DNA in which characteristic for FRED sequence is coded. Functions of many products of 24 genes still are not known. Studied proteins, with FRED domain, play different roles in organism. Fibrinogen is responsible for blood clotting, angiopoietins regulate new blood vessels formation, fibroleukin and ficolins are important in immune system response, and tenascines intermediate in cell and matrix interactions. The common feature, besides FRED domain, is participation in differentiation and migration of neoplastic cells. Many of FRED proteins may be potential markers of neoplasm diagnostics and application in therapies also can not be excluded.