Three pellets from each of 68 YRI LCLs were independently thawed, cultured, split, pelleted, and stored at −80°C. Pellets from each independent freeze-thaw were resuspended in 1.0 ml of 1.5% SDS lysis buffer (240 mM Tris-acetate, 1.5% w/v SDS, 0.5% w/v glycerol, 5 mM EDTA) containing 50 mM DTT, protease (1 μg/ml aprotinin, 1 μg/ml leupeptin, 1 μg/ml pepstatin), and phosphatase inhibitors (1 mM sodium orthovanadate, 10 mM β-glycerophosphate). To ensure complete protein denaturation, samples were boiled for 10 min, sonicated for 10 min (alternating 30 s on, 30 s off) with a Bioruptor (Diagenode), and concentrated to 5–10 μg/μl in a 96-well microconcentration device with a 10 kDa molecular weight cutoff (Millipore).