Dihydrohomofolic acid is a substrate for dihydrofolate reductase that produces tetrahydro-homo folate which in turn suppresses thymidylate synthetase and then DNA synthesis.
Homopteroic Acid is an intermediate in the synthesis of Homofolic Acid which inhibits the growth of L1210 mouse leukemia cells when intracellular folates are acquired via the high-affinity folate binding protein.