The human epidermal growth Factor Receptor 2 (HER2) gene encodes ErbB2, a TKI receptor of the EGFR family and regulates the downstream activation of several oncogenic pathways in the NSCLC context (extracellular signal-regulated kinase—ERK, MAPK, PI3K–Akt) [17,47]. The gene discussed is PIK3CA; the disease is non-small cell lung carcinoma.