Induces cardiac myocyte hypertrophy in vitro. Binds to and activates the ILST/gp130 receptor. Highly expressed in heart, skeletal muscle, prostate and ovary. Lower levels in lung, kidney, pancreas, thymus, testis and small intestine. Little or no expression in brain, placenta, liver, spleen, colon or peripheral blood leukocytes. Belongs to the IL-6 superfamily.