Figure 3. Rapamycin suppresses the emergence of senescent cells and spontaneous keratinocyte differentiation. (A) Phase contrast picture of primary keratinocytes cultured in CnT-07 medium in the absence (left panel) or presence (right panel) of rapamycin. (B) The large keratinocytes seen in (A) were stained positive with antibodies against p16 (in green), involucrin (red) or both, p16 and involucrin (yellow). Nuclei were stained with DAPI.