GABBR2 and breast carcinoma: To assess in vivo the cancer roles of GSDMB isoform 2 (GSDMB2), a transcript that promotes invasive and metastatic behavior of MCF7 breast cancer cells (Hergueta-Redondo et al., 2014), we first generated a conditional KI model (R26-STOP-GB2) and then derived the model (R26-GB2) ubiquitously expressing GSDMB2-HA and GFP transgenes in the whole body of the animal (Materials and Methods and Figures 1A–D).