For example, a normal tissue sample can be compared against a corresponding tumour to determine which genes tend to be more (or less) active.
It was known before the genomic era that clustered genes tend to be functionally related.
As a result, those genes that cause parents to invest unequally in the sexes will tend to be selected against.
Considerable evidence has already shown that related genes tend to exist as clusters in the genome.
And useless genes tend to get lost.
These have been reviewed, but, in essence, genes for atopy tend to be involved in allergic responses or other components of the immune system.
For reasons that remain unclear, the two genes tend to cancel each other out.
Over time I have come to see that my genes in my offspring tended to dominate, and this has sometimes caused grief.
These genes will then tend to numerically meet any given fold change cut-off even if the gene is not truly differentially expressed.
Active genes, which are generally found in the euchromatic region of the chromosome, tend to be located towards the chromosome's territory boundary.