Next, we established the xenograft tumor model by subcutaneously injecting EGFL7-knockdown PC9OR cells and control cells into the armpit of nude mice, and found that knockdown of EGFL7 resulted in a slower growth rate of xenograft tumors when mice were treated with osimertinib, as measured by tumor volume (Fig. 2D), tumor weight (Fig. 2E) and the levels of proliferative marker Ki67 (Fig. 2F). The gene discussed is EGFL7; the disease is neoplasm.