,27 To identify potential histone Kla sites trigged by hypoxia in ESCC, we performed a stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomic analysis coupled with Kla affinity enrichment to characterize the landscape of histone Kla in the KYSE30 cells (Figures 2B, 2C, S2A, and S2B). The gene discussed is KL; the disease is esophageal squamous cell carcinoma.