TCF21 and metabolic syndrome: 28 CXCL12 has also been shown to interact with the transcription factor TCF21 to inhibit ABCA1 expression.29 On the other hand, ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) are lipid transporters that modulate lipid homeostasis and, when dysregulated, lead to dyslipidemia.29 We observed higher CXCL12 transcripts in the aorta of PLWH and lower ABCA1 and ABCG1 compared to the PWoH control (Figure 4d).