In contrast, stable silencing of MZF1‐AS1 in IMR‐32 and BE(2)‐C cells led to reduction of 13C glutamine‐to‐proline conversion, proline levels, protein synthesis, cell viability, anchorage‐independent growth, and invasiveness in vitro (Figure S4C–F, Supporting Information), and significantly decreased the growth, tumor weight, and Ki‐67 proliferative index of xenograft tumors in nude mice (Figure S4G, Supporting Information). Here, MKI67 is linked to neoplasm.