A. siRNA mediated knockdown (KD) of candidates was repeated with four individual On Target Plus oligos incubated with HeLa cells for 48 hours. The results for POH1 were consistent. The knockdown of other candidates (MYSM1, USP14, BAP1, etc) with four individual oligos failed to show significant effects on ErbB2 levels (results from MYSM1 shown as an example). Lysates were also probed with EGFR, Met, and tubulin antibodies. The effect of knock-down of POH1 on EGFR and Met levels was much less pronounced than for ErbB2. B. quantitation of ErbB2, EGFR, and Met receptors for POH1 knockdown cells (averaged from 3 experiments). C. HeLa cells were treated with POH1 siRNA (four individual oligos) or oligofectamine transfection reagent (control) for 48 hours before lysis and analysed by immunoblotting for Transferrin receptor (TfR), Hrs, STAM, AMSH, and tubulin. Knock-down of POH1 showed minor effects on the levels of these proteins.