log2 gene expression vs. a quantitative trait

Question

[unsupervised_learning]

Hi,

I'm not an expert in gene expression analysis so I apologize if my question seems simplistic. I am using Allen Human Brain Atlas which consists of 6 subjects and their gene expression profiles for almost all genes. These data have been normalized across batches, within subjects and across subjects. The question is that whether it's possible to compare expression of a particular gene across subjects (i.e., log2(gene expression) of subject 1 > log2(gene expression) of subject 2) ? I'd like to show that expression of a gene in an individual is related to a quantitative trait of that individual.

Thanks