Acts as a positive regulator of ERK phosphorylation downstream of fibroblast growth factor-receptor activation (PubMed:23862974, PubMed:28157540). Involved in the regulation of both caspase-dependent apoptosis and caspase-independent cell death (PubMed:15178406). In the skin, it plays a predominant role in suppressing caspase-dependent apoptosis in response to UV stress in a range of dermal cell types (PubMed:28157540). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Detected at apical cell-cell junctions. Colocalized with FGF receptors to the cell membrane (By similarity). Detected in basolateral and apical membranes of all tubular epithelia. Predominantly expressed in skeletal muscle and testis. Expressed in basolateral and apical membranes of all tubular epithelia. Expressed in thin ascending limb of the loop of Henle and the distal convoluted tubule. Expressed in all layers of transitional ureteric epithelium and in the ureteric smooth-muscle cells. Weakly expressed in heart, brain, placenta, kidney, pancreas, spleen, thymus, prostate, uterus, small intestine, white blood cells, stomach, spinal cord and adrenal gland. Is widely distributed in the CNS. Also detected in several tumor cell lines. Expressed in the skin (PubMed:28157540). Disease susceptibility is associated with variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.