The present invention relates to phenyl derivatives of formula (I) Formula (I)wherein (R1)n, R3, R4a , R4b , R5b and Ar1are as described in the description and their use in the treatment of cancerby modulating an immune response comprising a reactivationof the immune system in the tumor. The invention further relates to novelbenzofurane and benzothiophene derivatives of formula (III)and their use as pharmaceuticals, to their preparation, to pharmaceuticallyacceptable salts thereof, and to their use as pharmaceuticals,to pharmaceutical compositions containing one or more compounds of formula(I), and especially to their use as modulators of theprostaglandin 2 receptors EP2 and/or EP4.(see formula I)
