CD44 and gastric cancer: In 16 GC patients with NTRK amplification, the expression levels of NOS2, CD274 (also known as B7-H1 and PD-L1), KDR (VEGFR2), CD44, VEGFA–C, CTNNB1, and TGFBR1 were upregulated (≥2.0-fold change), while those of MUC6 and NQO1 were downregulated (≤−2.0-fold change) (Figure 1c).