Although NSCLC cells responded to BTZ by increasing the level of HSPA1 (Fig. 1E), we showed that this effect should not simply be considered an adaptive response to BTZ-induced proteotoxic stress, since neither selective HSPA1 knockdown, nor double HSPA1 and HSPA2 knockdown sensitized cells to BTZ (Figs 2J,K, 3F and S1J,K). The gene discussed is HSPA2; the disease is non-small cell lung carcinoma.