Transcriptional profile of populations of normal human epidermal keratinocytes expressing p16INK4A. NHEKs were transduced with p16INK4A in three independent experiments resulting in keratinocyte populations expressing p16INK4A at different levels: LOW (18-fold), MEDIUM (60-fold) and HIGH (116-fold). Cell extracts were analysed 5 days following expression of the transgene by RT-qPCR for induction of transcript levels of (a) HOPX, HIST2H2BE, ICEBERG and S100A7 (S100A7/S100A15); (b) Cyclin A2 (CCNA2) and Cyclin D1 (CCND1) and (c) effectors of senescence-associated cell cycle arrest p14ARF, p16INK4A and p53. Data are reported as a fold increase in mRNA expression levels relative to the respective empty vector (EV) control. Legend: EV, NHEK expressing empty vector control; p16, NHEK expressing p16INK4A.