**20**wrote:

Hello Community,

The paper of DESe1 says that the forumula (6) :

A parametric curve of the form (6) is fit by regressing the gene-wise dispersion estimates α_g^wi onto the means of the normalized counts, μ̄ i via a gamma-family GLM regression.

Wihtin the Source code of DESeq2 I found the following code:

```
# Estimate a parametric fit of dispersion to the mean intensity
parametricDispersionFit <- function( means, disps ) {
coefs <- c( .1, 1 )
iter <- 0
while(TRUE) {
residuals <- disps / ( coefs[1] + coefs[2] / means )
```

So am I right that one assumes something like that? Atr = a1 / m + a0 + error

Atr /( a1 / m + a0 ) = error /( a1 / m + a0 ) mit epsilon = error /( a1 / m + a0 )

Atr /( a1 / m + a0 ) = epsilon ~ Gamma(a0, a1)

Thank you in advance

**25k**• written 6 months ago by Fischer-philipp •

**20**