Gel bands. Each gel band was subjected to an in gel tryptic digestion and extraction as described [77] . Dried samples were reconstituted with 12 mL of 3% acetonitrile (ACN) with 0.1% trifluoracetic acid. Nano-LC (nLC) separation of tryptic peptides was performed with a nanoACQUITY system (Waters), equipped with a Symmetry C 18 5 mm, 20 mm6180 mm trapping column and a UPLC BEH C 18 1.7 mm, 15 cm675 mm analytical column (Waters). The samples were transferred to the trapping column using a 5 mL partial loop injection with a 0.1% solution of formic acid (FA) in water at a flow rate of 7 mL/min for 3 min. Mobile phase A consisted of 0.1% FA in water and mobile phase B consisted of 0.1% FA in ACN. Following desalting and concentration, the trapping column was subjected to a reverse flush to the analytical column and separated with a gradient of 2-40% mobile phase B over 60 min at a flow rate of 300 nL/min, followed by a 5 min rinse with 95% of mobile phase B. The column was re-equilibrated at initial conditions for 20 min. Column temperature was maintained at 35uC. 100 fmol/mL [Glu 1 ]-fibrinopeptide B in 25% ACN with 0.1% FA was used as the lock mass compound and was delivered via the auxiliary pump of the LC system at a flow rate of 300 nL/min to the reference sprayer of the NanoLockSpray source of the mass spectrometer. The eluent from the analytical column was delivered to the analytical sprayer of the same source through a PicoTip emitter (New Objective, Woburn, MA) with 10 mm tip diameter.