FOS and neoplasm of testis: For example, in gastrointestinal stromal tumours, DNMT1, DNMT2, DNMT3B and DNMT3L are highly expressed compared to non‐tumour tissues,24 and DNMT3L in testicular tumours is specifically expressed.25 DNMT3L is a key factor affecting cell differentiation and tumour formation, and early studies have confirmed its transcriptional repression.18 A previous study found that transcription factors such as FOS, MAFK, E2F3 and EGR1 could be interacted with DNMT3L through transcription factor array experiments, further suggesting that EGR1 may form a complex with DNMT3L.26