The present invention provides nucleic acid and amino acid sequences that identify and encode a novel human map kinase homolog (SMAP) expressed in cells of the human stomach. The present invention also provides for PCR oligomers or hybridization probes for the detection of nucleotide sequences encoding SMAP or SMAP-like molecules, antisense molecules to the nucleotide sequences which encode SMAP, diagnostic tests based on SMAP encoding nucleic acid molecules, genetically engineered expression vectors and host cells for the production of purified SMAP, antibodies capable of binding specifically to SMAP, and agonists and inhibitors with specific binding activity for the polypeptide SMAP.