It has been found that in Drosha silenced GCa cells, miR-6778-5p positively regulates expression of its host gene serine hydroxymethyltransferase 1 (SHMT1), a key regulator in the folate-dependent serine/glycine interconversion, to mediate the compensatory activation of cytoplasmic carbon metabolism and in turn plays an important role in maintenance of the stemness of gastric cancer stem cells (GCSCs) (Zhao et al., 2020). Here, SHMT1 is linked to gastric cancer.