LIF (leukemia inhibitory factor) is a pleiotropic cytokine belonging to the interleukin-6 family that signals through a receptor complex consisting of LIF receptor β and gp130, activating JAK/STAT, MAPK, and PI3K pathways 1. Despite using common signaling mechanisms, LIF exhibits paradoxically opposite effects in different cell types, either stimulating or inhibiting cell proliferation, differentiation, and survival 1. LIF plays critical roles in maternal receptivity to blastocyst implantation, placental formation, nervous system development, and maintaining embryonic stem cell self-renewal and totipotency 1. In neural development, LIF regulates outer radial glial cell differentiation and promotes interneuron production in cortical cultures 2. LIF expression is widely distributed across human lung tissue, with the highest expression in fibroblasts, and is rapidly induced by inflammatory stimuli including IL-1β and anti-IgE 3. The cytokine's expression in monocytes is regulated by post-transcriptional mechanisms involving mRNA stabilization 4. In cancer, LIF promotes stemness and chemotherapy resistance through STAT3-SOX2 regulatory loops in head and neck squamous cell carcinoma 5 and pancreatic cancer 6. LIF knockout mice reveal that many of its cellular actions become apparent primarily during tissue damage or injury rather than normal development 1.