Expression of Bax and Bcl-XL. Top two panels: flow cytometric analyses of Bax expression. Sarcomatoid but not epithelioid cells responded to selenite treatment with a marked upregulation. Bottom four panels: flow cytometric analyses of Bcl-XL expression. Epithelioid cells lost Bcl-XL expression completely after selenite treatment, whereas sarcomatoid cells showed a partial loss. Gray histograms show the negative controls for the immunostaining. Three independent experiments were performed.