We first evaluated SBNO2 levels in tumour and normal tissues using TIMER and found that SBNO2 expression was significantly elevated in GC (P < 0.001), as well as bladder urothelial carcinoma, cholangiocarcinoma, oesophageal carcinoma, and head and neck squamous cell carcinoma (Figure 4(a)). Here, SBNO2 is linked to cholangiocarcinoma.