Supplementary methods nature REVISED 14

Supplementary methods Cell culture and preparation of SILAC media NIH3T3 (mouse fibroblasts, obtained from ATCC) and MCF7 (human breast cancer cells) cells were used and cultivated in SILAC medium at 37°C with 5% CO 2 and split every second or third day. SILAC media were essentially prepared as described previously 1. In essence, Dulbecco’s ................
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