The STK11 is a tumor suppressor gene located on chromosome 19p13.3. The encoded protein has serine--threonine kinase activity. Functionally, STK11 regulates cellular energy metabolism and cell polarity by activating AMP-activated protein kinase (AMPK) and other members of the AMPK family. Germline mutations in the STK11 gene are responsible for Peutz--Jeghers syndrome, an autosomal dominant disorder with variable clinical phenotype and increased risk of some cancers. Somatic mutations of STK11 gene are reported in several tumors including ~5% of cutaneous squamous cell carcinomas. According to Clinvar, this variant (c.597+1G>A) is considered to be oncogenic (https://preview.ncbi.nlm.nih.gov/clinvar/variation/265451/). This variant has been described as a germline variant that results in exon 4 skipping in a family with Peutz--Jeghers syndrome. Clinical correlation is recommended.