GEPIA2 was used to verify the differential expression levels of RECK, TIMP3, ERG, EHD1 and RASGRP1. The box plots generated by GEPIA2 showed that four genes (RECK, TIMP3, ERG and EHD1) were differentially expressed under the pre-set |log2FC| value and P value thresholds (Figure 6C-6G, P < 0.01) in at least one of the two lung cancers, with the exception of RASGRP1. The results of our RT-qPCR experiment also proved that the has-miR-21-5p expression in lung cancer tissues was significantly high (Figure 6H) (P < 0.01), and the specific expression information was shown in Table S8. Here, ERG is linked to lung cancer.