IARS2 and Hirschsprung disease: The expression level of MiR‐215 in colon tissues of HSCR patients was significantly decreased, which was positively correlated with IARS2 expression and negatively correlated with SIGEC‐8 expression. miR‐215 inhibits SIGEC‐8 by directly binding to the 3 ′‐UTR of SIGEC‐8