Hi, I read a lot of papers and I found that they didn't indicate what kind of values are used in t-test or logistic regression. Here is part of my data. The miR-29b-3p is the target gene and RNU48 is the internal control in my study. The dCT is calculated by CT of miR-29b-3p minus CT of RNU48.

I want to find differentially expressed genes between patients with good treatment responses and patients with poor treatment responses. So, should I use dCT or 2^-dCT to perform the t-test and logistic regression to predict their response? I built a logistic regression model and I found that the AUC is smaller if I use 2^-dCT to compute. But, if I use dCT, the AUC increased from 0.65 to 0.75. I don't know which is correct. Correct me if I am wrong. Please help me, thank you.