The abnormal composition of apolipoproteins (apo) in the lipoprotein fractions from the patient (P) is compared with the compositions of his mother (M) and a normolipidemic control participant (C). Equal amounts (20 μg) of total protein were run in each lane. Six antibodies were used against the following: apoB-100, apoA-IV, apoE, apoA-I, apoC-IV, and apoC-III. IDL indicates intermediate-density lipoprotein; LDL, low-density lipoprotein; and VLDL, very low-density lipoprotein.