Consistent with the crucial roles that Sp1 and E2F1 play in the modulation of miR-203 transcription, overexpression of E2F1 in T24T(shXIAP) cells markedly increased the cancer cell invasion, while knockdown of Sp1 in T24T cells significantly inhibited the cancer cell invasion (Fig. S5E, F). Here, SP1 is linked to cancer.