Heterocyclic compounds are described that are lysophosphatidic acid receptor ligands that are useful in the treatment of lysophosphatidic acid receptor-dependent diseases and conditions, including but not limited to diseases involving fibrosis, such as fibrosis of the heart, kidney, liver and lung, and scleroderma; inflammatory diseases such as diabetic nephropathy and inflammatory bowel disease; ocular diseases such as diseases involving retinal degeneration; nerve diseases such as pruritus and pain. Non-limiting examples of those compounds include (RS)-3-Cyclopropyl-2-{4-[3-methyl-4-((R)-1-phenyl-ethoxycarbonylamino)-isoxazol-5-yl]-benzyloxy}-propionic acid and (R)-1-(4′-{5-[1-(2-Chloro-phenyl)-ethoxycarbonylamino]-4-fluoro-pyrazol-1-yl}-2-fluoro-biphenyl-4-yl)-cyclopropanecarboxylic acid.