For example, at baseline, in adult males, but not females, manifesting depression-like behavior, a high level of the TNF protein persists for 3 months in the hippocampus and prefrontal cortex (Berkiks et al., 2018b, a) along with normal levels of IL-6 (Kvichansky et al., 2021; Table 5). This evidence concerns the gene IL6 and depressive disorder.