Q. A 52-year-old male presents to the clinic for a regular check-up. He has a past medical history of coronary artery disease and underwent coronary artery bypass graft surgery 5 years ago. The patient reports no current symptoms but is concerned about some skin lesions that have developed on his palms over the last few months. On examination, yellowish papules are present on the palmar creases of both hands. Lab work shows elevated levels of total cholesterol and triglycerides. Other components of the lipid panel, including HDL and LDL cholesterol, are within normal limits. Based on the clinical findings, which apolipoprotein is most likely deficient in this patient?