Putative inactive protein kinase which regulates signaling downstream of immune receptors including IL1R and Toll-like receptors (PubMed:10383454, PubMed:29686383). Inhibits dissociation of IRAK1 and IRAK4 from the Toll-like receptor signaling complex by either inhibiting the phosphorylation of IRAK1 and IRAK4 or stabilizing the receptor complex (By similarity). Upon IL33-induced lung inflammation, positively regulates expression of IL6, CSF3, CXCL2 and CCL5 mRNAs in dendritic cells (PubMed:29686383). Monomer (PubMed:33238146). Homodimer; disulfide-linked (PubMed:33238146). May interact with IRAK4 (when phosphorylated) (PubMed:33238146). Interacts (when phosphorylated at Ser-110) with PIN1 (via WW domain) in response to IL33-mediated (but not TLR4 ligand LPS) dendritic cell stimulation (PubMed:29686383). In dendritic cells, translocates into the nucleus upon IL33 stimulation. Expressed in eosinophils, dendritic cells and/or monocytes (at protein level) (PubMed:29686383). Expressed predominantly in peripheral blood lymphocytes (PubMed:10383454). The nucleotide binding domain binds ATP with low affinity. Disease susceptibility is associated with variants affecting the gene represented in this entry. Belongs to the protein kinase superfamily. TKL Ser/Thr protein kinase family. Pelle subfamily. Ser-293 is present instead of the conserved Asp which is expected to be an active site residue. Low level autophosphorylation activity has been reported in PubMed:10383454, while other authors describe this as an inactive kinase.