A: Box plots of the proinsulin-processing ratios [(insulin/total proinsulin+insulin) and (proinsulin fragments/total proinsulin)] in healthy control group, IR-ISL group, II-ISL group, and pancreas group before arginine injection (basal values). B: Box plots of the proinsulin-processing ratios [(insulin/total proinsulin+insulin) and (proinsulin fragments/total proinsulin)] in healthy control group, IR-ISL group, II-ISL group, and pancreas group during peak stimulation after arginine injection (stimulated values). Data are expressed as median (solid line), interquartile range (box), and range (whiskers). I/TP+I, insulin/total proinsulin+insulin; PF/TP, proinsulin fragments/total proinsulin.