Cytoplasmic c-Fos induced by the YXXQ-derived STAT3 signal requires the co-operative MEK/ERK signal for its nuclear translocation.

A STAT3 (signal transducer and activator of transcription 3)- and a MEK/Erk-mediated signal can be activated by cytokines, including IL-6 (interleukin-6), PDGF, and EGF. Recently, STAT3 and an ERK-signal were shown to co-operatively activate the c-fos gene. Activation of a truncated form of the IL-6 receptor subunit, gp130, that had only one YXXQ motif, induced both c-Fos and JunB in NIH3T3 cells through STAT3 without an apparent increase in the AP-1 (activator protein-1) activity.

Papular-purpuric gloves-and-socks syndrome with bloody bullae.

Papular-purpuric gloves-and-socks syndrome (PPGSS) is a disease characterized by itchy, painful acral erythema with edema, confluent papules, and purpura in a gloves-and-socks distribution and is associated with fever and mucosal lesions. Parvovirus B19 and other viral infections have been proven to be causative agents of this syndrome. Its histological findings have been the non-specific ones of interface dermatitis.