Abstract: A conjugate provided. The conjugate is a compound represented by Formula (I), or the conjugate is a stereoisomer, tautomer, homologue, solvate, metabolite, pharmaceutically acceptable salt, or prodrug of the compound represented by Formula (I): where A is a linker, and B is a dihydrofolate reductase inhibitor; R1, R2, R3, R4, and R5 are independently selected from H or C1-6 alkyl; and n1, n2, and n3 are each an integer selected from 0 to 6.