This substance is used in the treatment of cancer by regulating the immune response, including the recovery of the tumor's immune system. Benzofuran and benzofuran derivatives and their use as medicines, their formulation, acceptable salts for medicines and their use as medicines, and pharmaceutical compounds containing one or more of these compounds can also be supplied. In particular, it is used as a modulator for EP2 and/or EP4 receivers of prostate II. Requirement 1: A formula (1) compound for the treatment of cancer.In this case, cancer can be treated by modulating the immune response, including the recovery of the tumor's immune system； in this case, the compound can be used in combination with one or more chemotherapeutics and/or radiotherapy and/or targeted therapy； In formula compound (1): the ring (a) in formula fragment (2) represents five to six aromatic rings or five to seven non-aromatic rings, which are combined with phenyl. The independent ring (a) can selectively contain one or two non-atoms without nitrogen, oxygen and sulfur.(R1) 8345 as an alternative to the debris；Where (R1) 8345 represents one, two, three or four alternatives, these alternatives to R1 are selected independently of C8321833183323 asphalt；Alquenilo C83228331-83323；1. C83228331 tar；Alcoxi C8321883318323237A,Halogen, S-tar C8321833183323,Calcium fluoride C8321C833183323；Hydrogen fluoride C83218C833183323；Ciano, Oxo, -N8311； RN831222, in which RN8311 and RN831222 stand for hydrogen or alkyl C832183318324 independently；R3 represents hydrogen, methyl or trifluorobis； R8308； 7491 and R8308； 74955 represents hydrogen, methyl or R8308l independently； 7491 and R8308； 7491 and R8308； 7495 and its associated carbon atoms represent a cyclopropane-1, 1-diilo group； R8309； 7491 and R8309； 74955 represents hydrogen independently； A. Methyl, namely R8309； 74919 and R8309； 74955, together with the associated carbon atoms, represents a cyclopropane-1, 1-diacyl； AR1 represents a phenyl, or isopropy
