"Housekeeping gene" refers to a gene that is constitutively expressed in all cells of an organism. This term is often used in molecular biology to describe genes that are critical for the maintenance of cellular functions. Although "housekeeping gene" is a commonly used term, it has faced some criticism due to its implication that these genes are mundane or unimportant. As a result, scientists have begun to use alternative terminologies that are more descriptive and less stigmatizing. Some of the synonyms for "housekeeping gene" include "constitutively expressed genes," "ubiquitously expressed genes," "core genes," and "reference genes." These terms better reflect the essential role these genes play in cellular homeostasis and allow for more precise communication within the scientific community.