m6A methylation: a process reshaping the tumour immune microenvironment and regulating immune evasion

N6-methyladenosine (m 6 A) methylation is the most universal internal modification in eukaryotic mRNA. With elaborate functions executed by m 6 A writers, erasers, and readers, m 6 A modulation is involved in myriad physiological and pathological processes. Extensive studies have demonstrated m 6 A modulation in diverse tumours, with effects on tumorigenesis, metastasis, and resistance. Recent evidence has revealed an emerging role of m 6 A modulation in tumour immunoregulation, and divergent m 6 A methylation patterns have been revealed in the tumour microenvironment. To depict the regulatory role of m 6 A methylation in the tumour immune microenvironment (TIME) and its effect on immune evasion, this review focuses on the TIME, which is characterized by hypoxia, metabolic reprogramming, acidity, and immunosuppression, and outlines the m 6 A-regulated TIME and immune evasion under divergent stimuli. Furthermore, m 6 A modulation patterns in anti-tumour immune cells are summarized.