IL-11 is scarcely detectable in the body fluids of healthy individuals, yet its serum levels are elevated in various pathological conditions, such as arthritis [70], acute pancreatitis [71], pancreatic cancer [72], lipedema [73], polycythemia vera [74], lung disease in patients with rheumatoid arthritis [75], and major cardiac events in chronic heart failure [76]. This evidence concerns the gene IL11 and acquired polycythemia vera.