Filter low express genes in microarray data

Question

[Chris]

Hi all,

Can't attach a photo here, so I describe the distribution of my microarray data from 1 to 11 with a normal distribution. Base on this, I think the data already normalized and log transformed. May I know which threshold should use to filter low express gene in this case? Thank you so much!

I got this when try to upload photo: image:Exceeded the maximum amount of images you can upload.