Similar data were obtained in KPL-4 (Fig. 1c) and four additional breast cancer cell lines (MDA-MB-468, BT-549, MCF-7, MDA-MB-231) albeit with varying kinetics and relationships to XBP1S, ATF4, and/or CHOP expression (Fig. S1a–d). This evidence concerns the gene DDIT3 and breast carcinoma.