(A, B) Adhesion assays show that the number of adherent U937 cells to fibronectin (Fn)-coated plates under hypoxic condition (1% O2) is significantly decreased compared to normoxic conditions (21% O2). (C, D) In normoxia, adhesion assays show that the number of adherent TM9SF4-siRNAs transfected U937 cells to fibronectin (Fn)-coated plates (TM9SF4-siRNA) is significantly lower than the number of adherent control-siRNA transfected U937 cells (c-siRNA). (E; F) Knockdown of TM9SF4 expression in TM9SF4-siRNA transfected U937 cells (TM9SF4-siRNA) was controlled by Western blot (E) and flow cytometry (F) analysis of TM9SF4 protein expression compared to control-siRNAs transfected U937 cells (c-siRNA). (A, C) Pictures of one representative experiment of adhesion assays are shown. (B, D, F) Data are presented as the mean of six independent experiments (n = 6) ± SEM; **, *** are p<0.01, p<0.001 respectively. (E) One representative experiment out of three is shown; actin is shown as internal control.