The invention discloses novel application of a human YTHDF1 (Youth-Tech-Health Domain Family Member 1) 
gene, that is, a human YTHDF1 
gene expression amount detection 
reagent is applied to preparationof 
lung cancer clinical diagnosis reagents, a human YTHDF1 
gene is applied to preparation of 
lung cancer medicines, compared with normal pulmonary epithelial cells, the YTHDF1 gene is highly expressed in 
lung cancer cells, 
RNA (Ribonucleic Acid) designed according to the YTHDF1 gene is capable of interfering slow viruses, inhibiting expression of YTHDF1, remarkably inhibiting proliferation of thelung cancer cells, retarding tumor 
cell division at a G0 / G1 phase and promoting 
cell apoptosis, inhibiting formation of 
nude mouse transplanted tumour, and furthermore the purpose of treating 
lung cancer can be achieved; YTHDF1 
gene knockout mouse tumor formation capability detection shows that 
cell proliferation is remarkably inhibited, and cell 
apoptosis is remarkably increased; the results show that the YTHDF1 gene can be used as a target for 
lung cancer treatment, and wide prospects are provided for development of 
lung cancer treatment medicines based on YTHDF1 genes in future.