Substituted urea compounds useful in the treatment of diseases and C1-3alkyleneOR3 conditions related to DNA damage or lesions in DNA replication are disclosed formula (I), wherein X1 is null, —O—, —S—, —CH2—, or —N(R1)—; X2 is —O—, . -£>. -, or —N(R1)—,—. . Y xs 0 or S; or =y represents two hydrogen atoms attached to a common carbon atom, —W is selected from the group consisting of heteroaryl, aryl, heterocycloalkyl, cycloalkyl, and C1-6alkyl substituted with a heteroaryl. or aryl group; R6 is —C≡C—R7 or heteroaryl; R8, R9, and R10, independently, are selected from the group consisting of halo, optionally substituted C1-6alkyl, C2-6alkenyl, C2-6alkynyl, OCP3, CF3, NO2, CN, NC, N(R3)2, OR3, CO2R3, C(O)N (R3)2, C(O)R3, N(R1)COR3, N(R1)C(O)OR3, N(R8)C(O)OR3, N(R1)C(O)C1-3alkyleneC(O)R3, N(R1)C(O)C1 -3alkyleneC(O)OR3, N(R1)C(O)C1-3alkyleneOR3, N(R1)C(O)C1-3alkyleneNHC(O)OR3, N(R1)C(O)C1-3alkyleneSO2.NR3, C1-3alkyleneOR3, and SR3; Methods of making the compounds, and their use as therapeutic agents, for example, in treating cancer and other diseases characterized by defects in DNA replication, chromosome segregation, or cell division also are disclosed.