Silencing of TYMS effectively sensitized both HuCCA and KKU-D131 to 5-FU, even at the lowest concentrations (e.g., 1 μM), confirming that TYMS is the target of 5-FU and its levels modulate 5-FU sensitivity in both the sensitive and resistant CCA cells (Fig. 6b; Supplementary Fig. S7). The gene discussed is TYMS; the disease is cholangiocarcinoma.