APOE and psoriasis: Campalani and colleagues found that there was an association between the apolipoprotein E gene (APOE) e4 (+3937C/+4075C) alleles and psoriasis, and demonstrated there was a 10% e4 allele frequencies increased in those patients with drug-induced hypertriglyceridemia; however, it is not statistically significant in their research (Campalani et al., 2006).