Notably, using the ‘multiple proteins by names’ and ‘Homo’ organism functions of the STRING ver.11.0 (https://string-db.org) protein–protein network visualization platform, we demonstrated molecular interaction between the molecular markers of PD including SNCA, TH, PLK2, and IR markers such as FOXA2, IRS1, INS, INSR, PPARGC1A/PGC-1α, and ADIPOQ, with an average node degree of 9.8°, average local clustering coefficient of 73.8%, and protein–protein interaction (PPI) enrichment p-value <1 × 10−16 (Figure 1D); where ‘nodes’ are ‘proteins’ and ‘edges’ are ‘interactions’. This evidence concerns the gene PLK2 and Parkinson disease.