乳腺癌起源于乳腺上皮细胞，原因是乳腺上皮细胞发生基因改变，导致随后组织稳态丧失。科学家们经过大量研究将乳腺上皮细胞分为几个不同的亚群，但依然无法完全了解上皮细胞异质性和分化谱。

　　加州大学欧文分校（University of California, Irvine）的科学家，在最新一期Nature Communication上发表文章，采用单细胞mRNA测序(ScRNAseq)分析来自7个不同乳腺增生病人的25,790个人乳腺上皮细胞的转录组，使用无偏聚分析揭示了三种不同的上皮细胞群的存在，一种是基底细胞，另一种是导管腔上皮细胞，分为激素分泌型L1和激素反应L2型细胞。

　　文章作者从单细胞测序数据发现，KRT8在L2型细胞中比L1性表达水平高。

　　为了阐述KRT8蛋白质表达异质性，作者选择了ProteinSimple Milo单细胞western blot。Milo可将细胞分为三个亚群：阴性，低表达，高表达。并可以准确计算各亚群细胞的百分比即数量。

　　L2 was also characterized by higher levels of KRT8 than L1

　　 To quantify protein expression in individual cells, we utilized a recently developed single-cell western blot application (ProteinSimple, Milo), which performs electrophoretic separation of the protein content of about 2000 cells per chip and subsequently probed with fluorescently labeled antibodies.

　　Applying single-cell western blotting to luminal and basal cells isolated by FACS identified three cell states, namely KRT8-negative, -low, and -high , which illustrates the usefulness of single cell Western blotting as a quantitative validation tool downstream of scRNAseq analyses.

　　单细胞基因测序+Milo单细胞western blot组合，可以从基因水平和蛋白质水平完整解析细胞异质性，阐述肿瘤发生，干细胞发育等关键生命医学问题。