In the case of the regression vector of the albuminuria model (See Figure ), discriminative features are similar in the amide bands and to a lesser extent in the 1200-1000 cm -1 region. In this case, VIP scores emphasize the significance of the positive bands assigned to Amide I (1650 cm -1 ) and Amide II (1548 cm -1 ), which show positive values directions in the regression vector, indicating that the model was driven by the presence and concentration of typical protein bands.