PCNA and gastric cancer: Fig 6 showed PFTK1 could promote proliferation by CCK-8, colony-forming assay. At the same time, PFTK1 increased the G1—S phase transformation according to flow cytometric, coinciding with the finding of PFTK1 in hepatocellular carcinoma [10]. Cyclin E was one of the important regulatory factors during G1-S phase transformation and Cyclin E protein could define as a prognostic factor for patients with gastric cancer [25]. Interestingly, PFTK1 level was increased after transfecting with Flag-PFTK1 consistented with PCNA, MMP2 and Cyclin E (Fig 7).