SPHK1 and urinary bladder cancer: Despite of Meng et al. found that increased SPHK1 expression is associated with poor prognosis in bladder cancer [21] and Qin et al. demonstrated SPHK1 contributes to cisplatin resistance through NONO/STAT3-axis in bladder cancer [43], the mechanism of action of SPHK1 in bladder cancer progression is poorly understood.