FAP and neoplasm: However, CRC tumor cores with positive expression of FAP also showed higher expression of other immunohistochemical parameters: There was a significant correlation between percentual FAP positivity and the expression of tumor protein p53 (p < 0.0001, Wilcoxon rank-sum test with continuous TP53 values; p < 0.0001, Fisher’s exact test with grouped TP53 values (aberrant/non-aberrant)).