In a set of four cell lines (primary keratinocytes, CHL-1 melanoma cells, Cal27 head and neck squamous cell carcinoma cells and ME180 cervical carcinoma) harboring a functional Ras-Raf-MAPK pathway, reduction of SNORD50A/B expression by specific Antisense Oligonucleotides (ASOs) triggers ERK1/2 and MAPK activation and reduces cell proliferation in vitro. The gene discussed is MAPK3; the disease is melanoma.