The function of CTF1 (cardiotrophin 1, ENSG00000150281) is as follows. Functions as a cytokine that binds to the LIF receptor complex (PubMed:8833032). The LIF receptor complex indeed consists of two signaling receptor subunits IL6ST/gp130 and LIFR that transduce the signal into the cell (By similarity). Functionnally, acts as a potent cardiac survival factor, and promotes cardiomyocyte proliferation and hypertrophy (PubMed:8833032). Mechanistically, ligand binding to LIFR, induces heterodimerization with IL6ST/gp130 activating JAK tyrosine kinases (JAK1 or JAK2 and to a lesser extent TYK2) bound to their intracellular domains (By similarity). These kinases subsequently phosphorylate IL6ST/gp130 and LIFR (By similarity). The tyrosine phosphorylated signaling receptors serve in turn as docking sites for recruitment and activation of signal transducer and activator of transcription STAT3 (By similarity). {ECO:0000250|UniProtKB:Q60753, ECO:0000269|PubMed:8833032}.