TBX4 and non-small cell lung carcinoma: However, low TTTY15 expression is associated with an increase in the TNM stage of non-small cell lung cancer; TTTY15 overexpression targets and affects T-box transcription factor 4 (TBX4) expression via DNA (cytosine-5)-methyltransferase 3A (DNMT3A)-mediated regulation, thereby suppressing the cell cycle progression and metastasis of non-small cell lung cancer cells [31].