In one embodiment, provided is a composition comprising a prostaglandin compound for modulating stem cell proliferation and/or differentiation in a mammalian subject. In another embodiment, the instant application is a composition comprising a prostaglandin compound for, which comprises a prostaglandin compound for modulating proliferation and/or differentiation of stem cells of a mammalian subject, in which the stem cells are contacted directly or indirectly with the composition of the invention.