The function of CLCF1 (cardiotrophin like cytokine factor 1, ENSG00000175505) is as follows. Functions as a cytokine, either alone or by forming a stable complex with soluble CRLF1 or CNTFR (PubMed:10448081, PubMed:10500198, PubMed:10966616, PubMed:11285233, PubMed:11294841). Binds to CNTFR complex (CNTFR, IL6ST/gp130, LIFR) or can signal via trans-signaling using soluble CNTFR subunits (PubMed:10966616, PubMed:11285233, PubMed:11294841). Mechanistically, ligand binding to CNTFR, induces dimerization of the IL6ST/gp130 and LIFR, which activates JAK tyrosine kinases (JAK1 or JAK2 and to lesser extent TYK2) bound to their intracellular domains (PubMed:11294841, PubMed:16782820). These kinases subsequently phosphorylate IL6ST/gp130 and LIFR (PubMed:11294841). The tyrosine phosphorylated signaling receptors serve in turn as docking sites for recruitment and activation of signal transducer and activators of transcription (STAT3 and to lesser extent STAT1) (PubMed:10448081, PubMed:10500198, PubMed:10966616, PubMed:11285233, PubMed:11294841, PubMed:16782820). Moreover, CLCF1/CLF heterodimer induces tyrosine phosphorylation of PTPN11, that associates with IL6ST/gp130-LIFR, which in turn recruits PIK3 protein kinase followed by AKT protein phosphorylation (PubMed:11294841). Participates in the survival of embryonic motor neurons (PubMed:10500198, PubMed:10966616). Also stimulates B-cells (By similarity). {ECO:0000250|UniProtKB:Q9QZM3, ECO:0000269|PubMed:10448081, ECO:0000269|PubMed:10500198, ECO:0000269|PubMed:10966616, ECO:0000269|PubMed:11285233, ECO:0000269|PubMed:11294841, ECO:0000269|PubMed:16782820}.