Recombinant Human LIF is a pleiotropic factor produced by numerous cell types which includes myelomonocytic lineages, T cells, fibroblasts, melanoma, liver, and heart. LIF promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. Other activities include the stimulation of acute phase protein synthesis by hepatocytes, stimulation of differentiation of cholinergic nerves, and suppression of adipogenesis by inhibiting the lipoprotein lipase in adipocytes. Mature human LIF (180 aa) shares 78%, 82%, 91%, 88 and 87% aa sequence identity with mouse, rat, canine, bovine, and porcine LIF, respectively. To reduce spontaneous differentiation, LIF is typically added to stem cell culture medium.

LIF is a pleiotropic cytokine with a variety of roles. It is involved in the induction of hematopoietic differentiation in normal and myeloid leukemia cells, induction of neuronal cell differentiation, regulator of mesenchymal to epithelial conversion during kidney development, and may also have a role in immune tolerance at the maternal-fetal interface (PMID: 29620145; 29391217; 29271384)