Ribothymidine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents.

3-Hydroxyphthalic anhydride is used to synthesize 3-hydroxyphthalic anhydride modified human serum albumin.

4-Thiouridine (4-SU) is a photoactivatable ribonucleoside analog that is widely used for RNA analysis, including short-range RNA-RNA crosslinking and nascent RNA labeling. The crosslinking thio moiety is attached directly to the nucleotide base, thus 4-SU