In the context of a presumed interplay between smoking and COVID-19, it is even more interesting when one realizes that all of these histone marks are somehow associated with mdig gene (GenBank: BE441202, https://www.ncbi.nlm.nih.gov/nuccore/BE441202) [10], a lung cancer-related, cell growth-regulating gene spanning ~30,000 base-pairs, located on chromosome 3 that was first identified in the alveolar macrophages of coal miners with a history of exposure to mineral dust. This evidence concerns the gene RIOX2 and lung cancer.