tokens: Investigating the intracellular signaling pathways induced by SDF-1 and TPO revealed some overlapping patterns of protein phosphorylation/activation ( mitogen-activated protein kinase [ MAPK ] p42/44 , MAPK p38 , and AKT [ protein kinase B ] ) and some that were distinct for TPO ( eg , JAK-STAT ) and for SDF-1 ( eg , NF-kappa B ) .