The function of CRLF1 (cytokine receptor like factor 1, Ensembl gene identifier ENSG00000006016) is as follows. Functions as secretory protein carrier chaperone that promotes cellular release (PubMed:10966616). Also functions as a cytokine subunit within the CRLF1-CLCF1 heterodimer, which engages the CNTF receptor complex (CNTFR, IL6ST/gp130, LIFR) (PubMed:10966616). As part of the CRLF-CLCF1 complex, binds 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). 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:10966616, PubMed:11294841). 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:10966616). May also play a regulatory role in the immune system (PubMed:9686600). {ECO:0000269|PubMed:10966616, ECO:0000269|PubMed:11294841, ECO:0000269|PubMed:9686600}.