LETMD1 and lung cancer: Indeed, RT–PCR results indicated that the deletion of MEN1 in lung cancer cells increased the instances of short splicing isoforms in the FAM189B, NUBP2, ENDOV and TARBP2 genes, but inhibited generation of the CPSF7, MRRF and LETMD1 splicing isoforms (Supplementary Figure S5K).