While Bockman also favored further investigation of NI due its potential association with pain in PCa [19], it was the cutting-edge study by Zhu et al. which for the first time demonstrated a robust correlation between the intrapancreatic expression of the nerve growth factor (NGF), the frequency of perineural invasion and the degree of pain sensation in PCa patients [29]. This evidence concerns the gene NGF and posterior cortical atrophy.