With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The Rolling Stones included Keith Richards.
text_B: Dopamine receptor D2 , also known as D2R , is a protein that , in humans , is encoded by the DRD2 gene .. protein. protein. gene. gene. receptor. receptor ( biochemistry ). After work from Paul Greengard 's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs , several groups -LRB- including those of Solomon Snyder and Philip Seeman -RRB- used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor .. dopamine. dopamine. receptor. receptor ( biochemistry ). antipsychotic drugs. antipsychotic. The dopamine D2 receptor is the main receptor for all antipsychotic drugs .. dopamine. dopamine. receptor. receptor ( biochemistry ). antipsychotic drugs. antipsychotic
not_related.