Reproduction HSF1-pSer³²⁶ sensitivity to BTZ in 293T cells. To assess the effect of high and low HSF1-pSer³²⁶ expression on BTZ (A) and etoposide (B) sensitivity, 293T cells were transfected with two HSF1-pSer³²⁶ mutants that mimicked high (solid line) and low (dashed line) HSF1-pSer³²⁶ patients, in addition to an empty vector as control (dotted line). (C) Effect of the 2 mutants on HSF1-pSer³²⁶ protein expression was confirmed by using western blot analysis.