In support of this idea, we found that overexpression of PIWIL1 promotes lung cancer cell migration/invasion (Figure 9), which is consistent with published reports [30]; and cells overexpressing PIWIL1 display increased protein levels of P4HA2, PLOD2, and collagen I to some extent (Figure 5 and Figure 6). Here, P4HA2 is linked to lung carcinoma.