APOE and pachyonychia congenita: As shown in Table 1 and Figure 2, PC patients presented a serum lipids difference from non-PC tumor patients in triglyceride (P=0.001), cholesterol (P=0.005), HDL (P<0.001), LDL (P=0.003), apolipoprotein A1 (P=0.001), apolipoprotein B (P=0.007), and apolipoprotein E (P<0.001).