GPRC5D and esophageal squamous cell carcinoma: Many trials are ongoing, as in the case of CD38, signaling lymphocytic activation molecule (SLAM) family member 7 (SLAMF7), CD44 variant 6 (CD44v6), CD56, G-protein-coupled receptor class C group 5 member D (GPRC5D), transmembrane activator and calcium-modulator and cyclophilin ligand (CAML) interactor (TACI), and New York esophageal squamous cell carcinoma 1 (NY-ESO-1).