S1PR2 and oral cavity squamous cell carcinoma: The effects of S1P/S1PR2 are cell type dependent; and it has been reported to induce tumour suppression in human anaplastic thyroid cancer [6], glioblastoma [12], B16 melanoma [11] and neuroblastoma cells [10] but also to accelerate metastasis of human adenocarcinoma [13] and oral squamous cell carcinoma (OSCC) cells [5].