Knockdown of FAM225B inhibits the proliferation of NPC cells in vitro and in vivo. (A) Relative expression level of FAM225B in CNE-2 and SUNE-1 cells transfected with si-NC or si-FAM225B. (B,C) CCK-8 assay was performed to determine the effect of FAM225B knockdown on the viability of CNE-2 (B) and SUNE-1 (C) cells. (D,E) FAM225B knockdown inhibited cell proliferation detected using colony formation assay. (F-H) SUNE-1 cells stably expressing sh-FAM225B or sh-NC were subcutaneously injected into nude mice (n=6). Representative images of the tumors (F), relative FAM225B expression (G), and tumor weight (H) from each group. *p < 0.05, **p < 0.01. CCK-8: Cell counting kit-8; FAM225B: Family with sequence similarity 225 member B; NPC: Nasopharyngeal carcinoma; sh-FAM225B: Short hairpin RNA targeting FAM225B; sh-NC: Short hairpin RNA negative control; si-FAM225B: Small interfering RNA targeting FAM225B; si-NC: Small interfering