CD44 and neoplasm: In our study, overexpression of FOXP1 in TICs resulted in decreased proliferation and sphere-forming capacity of TICs in vitro, and a decrease in stem cells markers (CD44, CD133, and ALDH1A3) and H3K9Me2 compared to control cells, which is consistent with its tumor suppressor function in NSCLC in tumor initiation and progression.