Nonetheless, in certain groups of subjects (e.g., patients with elevated TG levels, type 2 diabetes—T2D, obesity, or very low LDL levels), the value of LDL (obtained through calculation or directly measured) may underestimate the total concentration of cholesterol carried by LDL and the total concentration of ApoB-containing lipoproteins, thereby underestimating the risk of CV disease, whereas the measurement of non-HDL (or ApoB) is advised [77]. The gene discussed is APOB; the disease is obesity due to melanocortin 4 receptor deficiency.