Functional analysis of FOXD1 was then performed by creating depletion cell lines using si-FOXD1 or si-FOXD1#2 in HNE3 and C666-1 NPC cell lines, which were chosen based on their relatively high endogenous FOXD1 expression levels (Fig. 1C). The gene discussed is FOXD1; the disease is nasopharyngeal carcinoma.