For these purposes, ubiquitous expression was defined as the uniformity of expression across tissues regardless of the magnitude of expression whereas tissue-specificity was interpreted as a significant positive deviation from uniformity in one of multiple tissues.

What does it mean to be ubiquitously expressed?

adj. Being or seeming to be everywhere at the same time; omnipresent. u·biq′ui·tous·ly adv.

What is ubiquitous genes?

Ubiquitous: Present everywhere. The small protein called ubiquitin was so-named because it is present in all types of cells and its amino acid sequence is identical in all creatures from insects to humans.