With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The Boeing 707 is a four-engine jet airliner with a narrow-body.
text_B: Hepatocyte growth factor -LRB- HGF -RRB- -LRB- or scatter factor -LRB- SF -RRB- is a paracrine cellular growth , motility and morphogenic factor .. paracrine. paracrine. motility. motility. morphogenic factor. morphogen. It is secreted by mesenchymal cells and targets and acts primarily upon epithelial cells and endothelial cells , but also acts on haemopoietic progenitor cells and T cells .. haemopoietic progenitor cells. haematopoiesis. It has been shown to have a major role in embryonic organ development , specifically in myogenesis , in adult organ regeneration , and in wound healing .. myogenesis. myogenesis
not_related.