FOXQ1 and ductal breast carcinoma in situ: S1a-d). AP20187 treatment promoted the growth of DCIS-iFGFR1 cells with sh-NC expression, while the two independent DCIS-iFGFR1 cell pools with sh-FOXQ1-1/2-mediated knockdown of FOXQ1 expression showed much slower growth rates and failed to respond to AP20187-stimulated cell growth (Fig.