INSR and Insulin resistance: The ectodomain of IR has been shown to be cleaved5–7; importantly, the levels of its soluble fragment IR (sIR) composed of α-subunits linked with the extracellular region of β-subunits has been shown to correlate with insulin resistance in diabetic human patients and has even been suggested as a potentially superior glycaemic marker than glycoalbumin and hemoglobin A1c7,8.