Lung cancer is the leading cause of cancer-related deaths worldwide. The initiation and progression of lung cancer is the result of the interaction between permanent genetic and dynamic epigenetic alterations. DNA methylation is the best studied epigenetic mark in human cancers. Altered DNA methylation in cancer was identified in 1983. Within 30 years of this discovery, DNA methylation inhibitors are used clinically to treat a variety of cancers, highlighting the importance of the epigenetic basis of cancer. In addition, histone modifications, nucleosome remodeling, and micro RNA (miRNA)-mediated gene regulation are also fundamental to tumor genesis. Distinct chromatin alterations occur in all stages of lung cancer, including initiation, growth, and metastasis. Therefore, stage-specific epigenetic changes can be used as powerful and reliable tools for early diagnosis of lung cancer and to monitor patient prognosis. Moreover, since epigenetic changes are dynamic and reversible, chromatin modifiers are promising targets for the development of more effective therapeutic strategies against cancer. This review summarizes the chromatin alterations in lung cancer, focusing on the diagnostic and therapeutic approaches targeting epigenetic modifications that could help to reduce the high case-fatality rate of this dreadful disease.

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CD56+ T cells are a group of pro‐inflammatory CD3+ lymphocytes with characteristics of natural killer cells, being involved in antimicrobial immune defense. Here, we performed deep phenotypic profiling of CD3+CD56+ cells in peripheral blood of normal human donors and individuals sensitized to birch‐pollen or/and house dust mite by high‐dimensional mass cytometry combined with manual and computational data analysis. A co‐regulation between major conventional T‐cell subsets and their respective CD3+CD56+ cell counterparts appeared restricted to CD8+, MAIT, and TCRγδ+ T‐cell compartments. Interestingly, we find a co‐regulation of several CD3+CD56+ cell subsets in allergic but not in healthy individuals. Moreover, using FlowSOM, we distinguished a variety of CD56+ T‐cell phenotypes demonstrating a hitherto underestimated heterogeneity among these cells. The novel CD3+CD56+ subset description comprises phenotypes superimposed with naive, memory, type 1, 2, and 17 differentiation stages, in part represented by a phenotypical continuum. Frequencies of two out of 19 CD3+CD56+ FlowSOM clusters were significantly diminished in allergic individuals, demonstrating less frequent presence of cells with cytolytic, presumably protective, capacity in these donors consistent with defective expansion or their recruitment to the affected tissue. Our results contribute to defining specific cell populations to be targeted during therapy for allergic conditions.