As confirmed by ESCC cells (KYSE410, KYSE510) and normal epithelium of esophagus (HET-1A) obtained from Hunan Fenghui Biotechnology Co., Ltd. (Changsha, China) through qPCR, C2, CD14, RTP4, FCER3A, and SLC7A7 were highly expressed in KYSE410 and KYSE510 than normal cells (Figure 8A–8H). Here, C2 is linked to esophageal squamous cell carcinoma.