GPR4 and non-small cell lung carcinoma: We performed studies on four NSCLC and two SCLC human cell lines as well as on normal lung tissue, and as it is shown in Figure 1, we observed that S1P receptors (S1PR1-R5), LPA receptors (LPAR1-R5) as well as GPR4 and G2A for LPC are highly expressed by most of the LC cell lines.