To determine whether E2F3a and/or E2F3b expression had an effect on the chemosensitivity of LAD cells, transfection of E2F3a, E2F3b eukaryotic expression vectors and E2F3 interference vector (named pcDNA/E2F3a, pcDNA/E2F3b, and pSil/shE2F3, respectively) was performed in LAD cell lines and satisfactory transfection efficiency was achieved at 48 hours after transfection (Figure 3B). This evidence concerns the gene E2F3 and leukocyte adhesion deficiency.