MUC5AC and gastric cancer: In fact, depletion of HOTAIR upregulates genes implicated with cellular adhesion and mucin production including ASTN1, PCDHA1, and MUC5AC. The roles of each of these genes have been elucidated to some extant: ASTN1, is required for appropriate and timely migration of cerebellar granule cells 30; PCDHA1 belongs to the cadherin superfamily and mediate the formation and maintenance of specific synaptic connections 31; MUC5AC, whose expression of protein and mRNA is significantly decreased in gastric cancer tissue 32.