PLOD2 and neoplasm: Furthermore, collagen deposition and reverse transcription polymerase chain reaction (RT-PCR) analysis of collagen modification genes collagen 1 A1 (COL1A1), lysl oxidase (LOX), and Procollagen-Lysine,2-Oxoglutarate 5-Dioxygenase 2 (PLOD2) significantly increased under hypoxia, indicating that hypoxic gradients promote tumor cell migration (Eisinger-Mathason et al., 2013; Lewis et al., 2016).