Understanding the interplay between cM with atrial fibrillation/warfarin could potentially guide the consideration of atrial fibrillation risks in the use of immune checkpoint inhibitors (26), BRAF (Serine/threonine protein kinase B-raf)/MEK (mitogen-activated protein kinase; MAPKK) inhibitors (12), and other targeted therapies for late-stage metastatic cM patients, as well as raise awareness of cM risks in atrial fibrillation patients, or cM risks in using warfarin for preventing thrombosis of cM patients with atrial fibrillation. This evidence concerns the gene WNK2 and atrial fibrillation.