MAPK1 and hemoglobin measurement: SP may promote the formation of activated epidermal growth factor receptor (EGFR) complexes after binding to NK-1R, inducing transactivation of EGFR, activating the MAPK pathway, and inducing the activation of ERK2 and deoxyribonucleic acid (DNA) synthesis, thereby promoting the progression of HB (Castagliuolo et al., 2000).