Fig. 1

IL13Rα2 is overexpressed in metastatic basal-like breast cancers and is associated with poor survival. a Real-time polymerase chain reaction analysis of the candidate metastasis-promoting genes SMTN, AGTPBP1, IL13Rα2, IGF2BP2, VEGFA, HMGCS1, TRIB3, INHBA, INSIG1, and TMEM97 to examine their expression levels in the MI, MII, MIII, and MIV cells. *P < 0.05, **P < 0.01, ***P < 0.001. b Kaplan-Meier survival analysis for assessment of distant metastasis-free survival (DMFS) based on tumor IL13RΑ2 expression in 135 patients with grade 1, 377 patients with grade 2, and 196 patients with grade 3 breast cancer [25]. Survival curves were generated by using the Kaplan-Meier Plotter online tool based on data stratified at the lower quartile (lowest 25 % IL13Rα2 expression versus all others). Curves were compared by log-rank test. c Meta-analysis of the Memorial Sloan Kettering Cancer Center primary breast tumor cohort [23] was performed to identify associations between IL13Rα2 expression levels and basal versus luminal breast tumor subtypes; estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor 2 (Her2) receptor status; and patient prognosis. Tumors were stratified on the basis of the median IL13Rα2 expression levels in low- or high-expression groups. Breast tumor subtypes were determined on the basis of the expression of keratin 5 and keratin 17 (basal) or keratin 8 and keratin 18 (luminal) markers [26]. Statistical significance was assessed by using chi-squared analysis. *P < 0.05. IL13Rα2 interleukin-13 receptor alpha 2