If we use the above two OPG values (8 and 16.3 pmol/l), we could identify three groups of AL patients with different survival: those who had an OPG value of ⩽8 pmol/l, those with OPG between 8 and 16.3 pmol/l, and those with OPG⩾16.3 pmol/l with median OS of 91, 47 and 12 months, respectively (Figure 3c). This evidence concerns the gene TNFRSF11B and axial length measurement.