CD4 and neoplasm: PMA promoted NETs formation in tumours of mice, increased the number of CD3(+)CD4(+) T cells, decreased perforin, granzyme A, granzyme B, IFNγ, and TNF‐α levels, and promoted LUAD growth and the number of lung tumour nodules, indicating that PMA promoted NETs formation, reduced the activity of CD8(+)T cells, and promoted LUAD growth.