RIPK4 and tongue squamous cell carcinoma: Interestingly, in addition to promoting tumour progression, other related studies have found that RIPK4 can also inhibit tumour progression; for example, RIPK4-mediated inhibition of STAT3 signalling slows the progression of lung cancer (Kopparam et al., 2017) and plays a role in inhibiting tumour progression in tongue squamous cell carcinoma and squamous cell carcinoma of the skin (Xinhua et al., 2014) (Chen et al., 2017).