HOPX , HIST2H2BE , ICEBERG and S100A7 / S100A15 transcripts in keratinocytes transduced with p14ARF, p16INK4A, p53 and TRF2ΔBΔM. (a) Candidate markers HOPX, HIST2H2BE, ICEBERG and S100A7 (S100A7/S100A15) expression levels reported as a fold change in transcript relative to the respective empty vector (EV) control. Data are mean ± sd for two independent experiments (n = 2) corresponding to NHEK populations expressing MEDIUM and HIGH levels of the transgenes p14ARF, p16INK4A, p53 and TRF2ΔBΔM. (b) Representative blot of S100A7 protein levels for the same NHEK populations. Legend: GFP, NHEK expressing pBabe-GFP empty vector; p14, NHEK expressing pBabe-p14ARF; p16, NHEK expressing pBabe-p16INK4a; p53, NHEK expressing pBabe-p53; EV, NHEK expressing pLPC empty vector; DN, NHEK expressing pLPC-TRF2ΔBΔM; (+) symbol, positive control (terminally differentiated NHEK); (-) symbol, negative control (telomerase-positive SCC-25 cell line).