BAFF and APRIL increase malignant HRS cell survival and proliferation. (A) Viability, death, and proliferation of serum-starved HD-MyZ HRS cells incubated for 2 days in the presence or absence of BAFF, APRIL, CD40L, or CD30L as described in “Materials and methods.” Bars indicate SD of 4 experiments; *P < .05 versus cells incubated with medium, respectively. (B) BAFF and APRIL expression on HD-MyZ HRS cells incubated for 2 days with medium (shaded profiles), or CD40L or CD30L (open profiles). Positive cells are on the right of the vertical bar. On the left of this bar are cells stained with a control mouse (for BAFF) or rat (for APRIL) antibody with irrelevant binding activity. One of 3 experiments yielding similar results. (C) Bcl-2, Bcl-xL, Bax, c-Myc, and actin proteins in HD-MyZ HRS cells incubated as in panel A. Bands were quantified (numbers below lanes) after normalization to the actin loading control. One of 3 experiments yielding similar results. (D-E) Apoptosis and proliferation of HD-MyZ HRS cells exposed to BAFF or APRIL in the presence or absence of the anti-HL agent doxorubicin (Doxo). Bars indicate SD of 3 experiments; *P < .05 versus cells incubated with Doxo.