BCL2L1 and breast carcinoma: According to The Human Protein Atlas (https://www.proteinatlas.org), at the cellular level, BCL-xL has low RNA cell specificity, as it can be detected in several cell lines such as Caco-2 (colon cancer), MCF7 (mammary gland cancer), HeLa (breast cancer), A549 (lung cancer), etc. In all these cell lines, intracellular localization of BCL-xL protein is mainly in the mitochondria.