To further investigate whether cancer cells cultured in a 3D matrigel microenvironment acquire stem cell–like characteristics when compared with 2D monolayer cells, we measured the expressions of the stem cell markers OCT4, SOX2, NANOG, c-MYC and LIN28 in both 2D- and 3D-cultured A549 cells. The gene discussed is POU5F1; the disease is cancer.