Dermatology is a branch of medicine which is developing rapidly both in terms of research on etiopathogenesis of diseases and in therapies. The presented papers comment on various topics from this area. These topics are often encountered in practice. I hope that the issues presented in this series of papers would be of interest for a wide spectrum of readers.

In the last decades, we have witnessed dynamic progress in the area of molecular biology.

An original collective paper pertains to molecular research of non-melanoma skin tumours (the Molecular Biology Department, the Dermatology Department and Clinic, the Medical Genetics Department, the Cosmetology Department, Institute of Structural Research of Skin of the Medical University of Silesia, Katowice). The molecular research was to specify diagnostic and prognostic markers that would supplement clinical diagnostics and to develop new therapies. A large molecular similarity between keratoacanthoma and spinocellular (squamous cell) carcinomas has been shown. The basal cell carcinomas group showed heterogeneity with two subgroups of different mRNA copies of MMP10 and MMP2 genes. MMP1 gene transcripts concentrations were significantly increased in every study group in comparison with the control group. The increase of the number of copies of MMP10 mRNA and the MMP2 decrease are likely candidates to be prognostic markers in patients with basal cell carcinoma. The potential universal target in the molecular therapy in non-melanoma skin carcinomas is metalloproteinase 1 encoding gene.

The next two original papers by Dr. hab. med. Anna Lis-Święty from the Dermatology Department and Clinic of the Medical University of Silesia and the Molecular Biology Department of the Medical University of Silesia concern applying of the real-time QRT-PCR technique to examine the number of copies of mRNA of the TGF-β1 and TNF-α encoding genes and their receptors in blood cells in patients with systemic scleroderma (SSc). The research implies that in the period before the SSc development (isolated RP), TGF-β1 gene expression in the blood cells is decreased. When the symptoms of the disease are visible, the expression increases again. The consequences of these changes might be unfavourable in both stages: the stage of vasomotor alterations and in the stage of fibrosis. On the other hand, disorders of the proportion of trans-membrane forms of TGF-β1 receptors may lead to abnormal activation of signalling pathways in cells, the consequence of which might be pathologic activation of certain processes.

In a paper concerning TNF-α, the authors have determined a decreased expression of this molecule in blood cells of SSc patients. It might be a decisive factor in the process of fibrosis because TNF-α is a principal anti fibrogenic cytokine. Significantly lower number of mRNA copies of TNF-αRI and TNF-αRII receptors than in the control group was shown. The increase of the proportion of TNF-αRI/TNF-αRII in SSc patients seems to indicate that TNF-αRI might be responsible for the fibrosis, while TNF-αRII might have the opposite effect.

An original paper from the Dermatology and Venereology Department and Clinic of the Medical University of Łódź deals with the problem of low folic acid concentration as one of the factors predisposing to the development of basal cell skin carcinomas and its deficiency might be deemed as one of factors increasing the risk of carcinogenesis in the skin.