PAI has shown promise in several biomedical applications, monitoring angiogenesis, evaluating blood oxygen saturation, conducting CNS functional imaging, assessing cortical blood volume, detecting skin and conjunctival melanoma depth, determining methemoglobin levels, tumor hypoxia, and lymph node metastasis (Wang et al., 2003; Shao et al., 2013; Yao and Wang, 2014; Rich and Seshadri, 2015; Khattak et al., 2019). This evidence concerns the gene HBG2 and metastatic malignant neoplasm in the lymph nodes.