CDKL2 and gastric cancer: High CDKL2 protein expression (IHC+) (42.3 months vs. not arrived, HR = 1.84 (1.38–2.82), p = 0.0002; Figure 4(a)) and increased CDKL2 copy number (FISH+) (40.6 months vs. not arrived, HR = 1.71 (1.12–3.39), p = 0.0193; Figure 4(b)) both predicted a worse OS of patients with GC compared to those with IHC- and FISH-, respectively.