- Total RNA from PFL-treated and untreated MKN28 cells was extracted and subjected to Aligent Expression Array Analysis with SurePrint G3 Human GE 8x60K v2 (Takara Bio, Japan). The expression level of each gene at each time was determined and compared with that of control RNA from PFL-untreated cells. Highlighting indicates more than a 2-fold change in the expression level.