MAPK8 and neoplasm: The protein “Eiger” is the close homolog for OX40L in T. castaneum and D. melanogaster eiger (egr) encodes the TNF superfamily ligand that activates the intracellular JNK pathway, which mediates cell death, tumor suppression, and growth regulation (Igaki et al., 2002; Shklover et al., 2015).