Aim: Circular RNAs (circRNAs), are nonprotein coding RNAs consisting of a circular loop with multiple miRNA, binding sites called miRNA response elements (MREs), functioning as miRNA sponges. This study was performed to identify differentially expressed circRNAs and their MREs in basal cell carcinoma (BCC). Materials & methods: Microarray circRNA expression profiles were acquired from BCC and control followed by qRT-PCR validation. Bioinformatical target prediction revealed multiple MREs. Sequence analysis was performed concerning MRE interaction potential with the BCC miRNome. Results: We identified 23 upregulated and 48 downregulated circRNAs with 354 miRNA response elements capable of sequestering miRNA target sequences of the BCC miRNome. Conclusion: The present study describes a variety of circRNAs that are potentially involved in the molecular pathogenesis of BCC.

Hidradenitis suppurativa (HS) is a chronic skin disease that predominantly affects the skin of the intertriginous area through an inflammatory process and results in recurrent nodules, abscesses, sinuses, fistulas, and scarring.^1,2 Because the precise description of HS may provide a challenge, considerable efforts have been made to formulate diagnostic criteria and validate clinical descriptive terms for the lesions occurring in patients with HS.^3,4 In addition, an international initiative (HS core outcomes set international collaboration) has started to develop a list of mandatory outcomes that should be measured in clinical trials on the treatment of HS.⁵ However, the variation in clinical appearance and the variability in response to a wide range of proposed treatments underline the importance of an accurate disease severity assessment tool.^1,6