Recently, two phase I clinical trials of the miR-29 mimics targeting histone deacetylase 4 (HDAC4) and MMPs (matrix metalloproteinases) in scleroderma patients and miR-155 inhibitors targeting SHIP (SH2-containing-inositol phosphatase) and RHOA (Ras homolog gene family,member A) in cutaneous T-cell lymphoma patients were initiated and placed great expectations. Here, HDAC4 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.