Consistent with previous observations, Tozlu et al. also showed that the expression of IL6ST and ER were significantly associated (p = 1.4 × 10−6) and positive expression of the signal transducer was highly predictive of ER+ status, perfectly discriminating between ER+ and ER- tumours (area under the receiver operating characteristic curve = 1) [43]. This evidence concerns the gene IL6ST and neoplasm.