Heat map of 35 MFs showing the change in abundance across multiple time point. A cluster analysis was performed on log2 transformed averaged abundances of individual MFs at each time point for samples of Expanded Discovery Set-1 (EDS-1) and the Qualification Set (QS). MFs are displayed in rows and noted by the monoisotopic mass of the MF. Columns display time points. Visual analysis of the heat map revealed four clusters (C1, C3, C6, C9) of MFs that behaved dissimilarly between qualification sets; five clusters (C2, C4, C5, C7, C8) of MFs that behaved similarly between qualification sets; and two MFs (*) that did not fit into a specific cluster because of the low abundance at D0. Red indicates high abundance, green indicates low abundance.