PROX1 and cancer: Prospero homeobox protein 1 (PROX1), a transcription factor related to organ development and cell fate determination,12, 13, 14, 15 is also expressed in various cancers acting either as a tumor suppressor or as an oncogene depending on the tumor type.16 In healthy gastric mucosa, miR‐489 inhibits PROX1 levels, while the loss of function mutations in gastric carcinogenesis directly results in increased PROX1 levels.17 Overexpression experiments involving miR‐489 resulted in the deceleration of growth and reduced PROX1 levels, suggesting that PROX1 may contribute to gastric carcinogenesis.