CDA and neoplasm: Thus, expression of CDA in combination with uracil phosphoribosyl-transferase in tumor cells increases the cellular sensitivity to 5-FC and 5-FU (Erbs et al., 2000; El-Kalyoubi et al., 2021, ​El-Mekawy et al., 2010, ​El-Sayed et al., 2010, ​El-Sayed et al., 2011).