OIP5 and estrogen-receptor negative breast cancer: Spontaneous CTA-specific immune responses against tumor cells are a feature commonly seen in other malignancies such as recently found in estrogen-receptor negative breast cancers [24], and they might also have an outcome on patients' overall survival, as described by Freitas M, et al., who reported the expression of the CTAs, ACTL8, OIP5, XAGE3 and CTCFL, as an independent predictor of better OS in glioblastoma [25].