While the human epididymis protein 4 (HE4) has been previously identified as a blood biomarker of fibrosis, the relationship HE4 has with other blood biomarkers has not been established.

A recognized link exists between oxidative stress, obesity and atrial fibrillation (AF). NADPH oxidase 2 (NOX2) serves as a significant contributor to reactive oxygen species (ROS) production in the heart, and it is known to be elevated in obese mice.