A cut of the peptide. When the peptide RGSphosDVEDASNAK is fragmented between the seventh and eighth residue, the predominant resulting species are b7 (RGSphosDEVD) and y5 (ASNAK). Seven peaks support the this cut of the peptide, each adding to the confidence in the assignment. Zoom-in images around b7 and y5 show the related ions (*) present in this cut. In the b7 image, related ions include b7 + 1 and b7 − 98. In the y5 image, related ions include y5 + 1, y5 − 17 and y5 − 18. Note the break in the y-axis scale.