CD44 and head and neck squamous cell carcinoma: In the head and neck squamous cell carcinoma cell lines HN-8, HN-30 and HSC-3, apigenin significantly downregulated the stem cell markers of CD44, NANOG, and CD105, and abolished the hypoxia-induced increase in CD44(+) cells, CD105(+) cells and STRO-1(+) cells [63].