你发现TCGA的样本里面并没有肿瘤grade信息，原来是因为~

Jimmy

这个肿瘤可能根本没有统一的grade判断标准，哈哈~~~~
所以样本收集人员没办法记录。

所以有文章专门讨论如何评定grade咯
比如这个：http://journals.plos.org/plosone ... ournal.pone.0138213
Identification of Gene-Expression Signatures and Protein Markers for Breast Cancer Grading and Staging
无非就是一堆基因的表达量的合集咯，号称signature呗。

Cancer grading is a measure of the malignancy and aggressiveness independent of stage. Unlike staging, cancer grading has been predominantly done through visual inspection of the cell morphology and tissue structure [3], generally lacking in using molecular level information. Compared to stage determination, it is a less developed area in cancer classification. Currently there is no universal grading system for all cancer types, instead research communities of a few cancer types each have developed their own grading systems such as the one for breast cancer developed by Bloom and Richardson [6], the Gleason system for prostate cancer [7] and the Fuhrman method for kidney cancer [8]. While there are some differences in the detailed classification criteria, these grading systems generally classify cancer tissues to four grades: well differentiated (WD), moderately differentiated (MD), poorly differentiated (PD) and undifferentiated (UD).


效果还不错，不同grade的一些基因表达差异很显著。