PTK2 and urinary bladder carcinoma: Similar to CYFIP2, most research about ST8SIA1 mainly focused on cancer, revealing that ST8SIA1 regulated tumor growth and metastasis by activating the FAK/AKT/mTOR signaling pathway in breast cancer (34, 35), or inhibited the progression and invasion of bladder cancer cells by suppressing the JAK/STAT signaling pathway (36).