What the data from "Expression 21q4 public" is based on?

I was wondering what the data from Expression public 21q4 is based on.

  1. How do they measure expression levels of each gene, is it based on RNA, protein levels, or something else?

  2. Is there anywhere I could find the methods for obtaining this dataset?

  3. How many samples per cell lines do they analyzed?

  4. Were the cell lines surely not under any experimental condition (which is really important regarding expression profiles)?

The expression data is derived from RNA sequencing. I’d recommend reading the README file which accompanies the 21Q4 data release for more information. You can find that file in the 21Q4 data release in the Download section of the portal.