In ESCC, circ-SLC7A5 [20], circ-LRP6 [21] and circ-TTC17 [22] have been reported to play tumor-promoting roles, but circFoxo3 [23] and circSMAD7 [24] act tumor-inhibiting roles. The gene discussed is SLC7A5; the disease is esophageal squamous cell carcinoma.