Repairable levels of DNA damage do not replicate the effects of telomere uncapping in keratinocytes. NHEKs were irradiated with 2 gray of IR and allowed 6 h to recover. Whole cell lysates were then prepared and analysed by reverse transcription quantitative PCR (RT-qPCR) and Western blotting for the indicated transcripts and proteins, respectively. (a) p21WAF transcript (graph), GAPDH, total p53 and p21WAF proteins (blot). (b) Cyclin A2 (CCNA2), cyclin D1 (CCND1) and involucrin (IVL) transcripts. (c) HOPX, HIST2H2BE, ICEBERG and S100A7 (S100A7/S100A15) transcripts. Data are reported as a fold change in mRNA expression levels relative to the non-irradiated control (0 gray). Data are mean ± sd from three independent measurements (n = 3) in (b) and (c); in (a), only two out of the three independent measurements are represented. Legend: GAPDH, loading control; (+) symbol, positive control for total p53 and p21WAF proteins (SVHFK cell line); last lane loaded with double the amount of total protein.