transmembrane 4 superfamilies. It is widely expressed in many tissues, but the exact function of the encoded protein is unknown. MAP3K9 on Chr14 encodes for a mixed lineage kinase including the serine/threonine kinase that acts as an essential component of the MAP kinase signal transduction pathway. It plays an important role in the cascades of cellular responses evoked by changes in the environment. It acts as an upstream activator of the MKK/JNK signal transduction cascade. The MKK/JNK signaling pathway regulates stress response. MAP3K9 also plays a role in mitochondrial death signaling pathway, leading to apoptosis. A bidirectional LncRNA is located in the promoter of MAP3K9, 777bp from the TSS. PCNX on Chr14 encodes a pecanex homolog expressed in the blood plasma. All risk variants at these six genes (i.e., PKNOX2, MREG, GPD1L, CMTM8, MAP3K9 and PCNX) are predicted to mildly to highly significantly alter the RNA secondary structure. Finally, OPA3 is involved in sensory perception, specifically visual perception. OPA3 is expressed consistently across human brain tissues. All of the five genes (PKNOX2, MREG, GPD1L, PCNX and OPA3) were expressed in rodent brain in the present study; however, their roles in alcohol dependence remain largely unclear.
