The conditional effects show that the regression for the HCC – OLBI association was significant for IL-18 concentrations of 81.7 pg/ml in older participants (p < .0001 to p < .05), for concentrations of 27.5 pg/ml in middle-aged group (p < .05), and for concentrations of 135.9 pg/ml in young adults (p < .05) as illustrated in Fig. 9a but the direction of the association changed between the age groups, showing a negative relationship in young age for high concentrations and a positive association in older adults. This evidence concerns the gene IL18 and hepatocellular carcinoma.