Because affective nicotine withdrawal signs, which are hypothesized to contribute more to relapse than somatic signs [29], [30], were attenuated in CaMKIV −/− mice, these results suggest that CaMKIV levels are increased after withdrawal from nicotine, and reducing CaMKIV gene expression alleviates certain aspects of nicotine dependence. This evidence concerns the gene CAMK4 and nicotine dependence.