In the HG group, based on the classification of ketonuria severity as level 1&2 and 3&4, the group was subdivided into 2 distinct subgroups to assess whether orexigenic neuropeptides (i.e., orexin and galanin) and anorexigenic neuropeptides (i.e., α-MSH and CART) can serve as markers for measuring the severity of HG via ROC analysis (Table 4. The gene discussed is GAL; the disease is Ketonuria.