Synj2, or synaptojanin 2, encodes an inositol polyphosphate phosphatase. It functions in recycling neurotransmitter vesicles and is implicated in spermatogenesis. It also plays a role in processes like protein digestion and absorption, extracellular matrix-receptor interaction, and is involved in regulating cell proliferation and apoptosis via dephosphorylating plasma membrane phosphoinositides [5,1,6].

Studies across multiple cancers have shown its significance. In lung squamous cell carcinoma (LUSC), SYNJ2 is upregulated at both mRNA and protein levels, predicting poor prognosis, and its cancer-promoting effect may be related to certain pathways [1]. In papillary thyroid carcinoma (PTC), it is highly expressed and may promote progression through angiogenesis and epithelial-mesenchymal transition (EMT) pathways [2]. In gastric cancer, SYNJ2 promotes cell metastasis and angiogenesis by up-regulating GRB2 [3]. Also, a variant rs9365723 on SYNJ2 is associated with colorectal cancer risk, especially colon cancer [4]. In hepatocellular carcinoma (HCC), upregulated SYNJ2 may accelerate its occurrence and development via metabolic perturbation pathways [6].

In conclusion, SYNJ2 has diverse functions in normal biological processes and is closely associated with multiple cancers. Research on SYNJ2 in these cancer models helps understand its role in tumorigenesis, potentially providing new insights for cancer prediction and treatment.