Figure 1. Mass spectrum and fragment ions of the peptide ²⁸¹YTCHVQHEGLPEPLTLR charge 3+, 684.01 m/z) which  is specific to the Putative HLA class I histocompatibility antigen, alpha chain H (P01893) missing protein encoded on human chromosome 6, identified using an open-source graphical user interface SearchGUI with simultaneous integrated search algoritms X!Tandem and MS-GF+.