SLC38A1 and neoplasm: Among those candidate genes, hsa_circ_0000396, which derived from exon 2 to 5 of solute carrier family 38 member 1 (SLC38A1) gene with a length of 522 nt, we designated as circSLC38A1, attracted our attention since SLC38A1 was essential for cell migration and tumor metastasis [28, 29].