Furthermore, in addition to the fact that this study was an in vitro experimental system using the SM-AP cell system, Cardoso et al. also reported that in their examination of HIF-1α levels as a hypoxia marker using surgical material from benign and malignant salivary gland neoplasms, no significant differences in HIF-1α expression were found [35]. The gene discussed is HIF1A; the disease is salivary gland neoplasm.