GRK6 and neoplasm: Representative results of the BSP analysis for the GRK6 gene promoter in LADC tissues and adjacent non‐tumor tissues are shown in Fig. 3B. The methylation frequencies of CpG sites within the GRK6 gene promoter in LADC tissues and adjacent non‐tumor tissues were 52 ± 7.8% and 23 ± 6.5%, respectively.