We also reiterate that S100β concentrations may be influenced by a number of factors, such as exercise, melanoma, dementia, sleep apnea, depression, time of year/season, bone fractures, muscle injury, and burns (Anderson et al., 2001, Chaves et al., 2010, Harpio and Einarsson, 2004, Koh and Lee, 2014, Mohammed et al., 2001, Morera-Fumero et al., 2013, Pelinka et al., 2003, Peskind et al., 2001, Polyakova et al., 2015, Traxdorf et al., 2016), only some of which (dementia and melanoma) were accounted for in the present analyses. The gene discussed is S100B; the disease is major depressive disorder.