Modified bases also occur in DNA. The first of these recognised was 5-methylcytosine which was found in the genome of Mycobacterium tuberculosis in 1925.  The complete replacement of cytosine by 5-glycosylhydroxymethylcytosine in T even phages (T2, T4 and T6) was observed in 1953  In the genomes of Xanthomonas oryzae bacteriophage Xp12 and halovirus FH the full complement of cystosine has been replaced by 5-methylcytosine.   6N-methyadenine was discovered to be present in DNA in 1955.  N6-carbamoyl-methyladenine was described in 1975.  7- methylguanine was described in 1976.  N4-methylcytosine in DNA was described in 1983.  In 1985 5-hydroxycytosine was found in the genomes of the Rhizobium phages RL38JI and N17.  α-putrescinylthymine occurs in both the genomes of the Delftia phage ΦW-14 and the Bacillus phage SP10.  α-glutamythymidine is found in the Bacillus phage SP01 and 5-dihydroxypentyluracil is found in the Bacillus phage SP15.
Adrucil is an analogue of uracil with a fluorine atom at the C-5 position in place of hydrogen. It rapidly enters the cell using the same facilitated transport mechanism as uracil. Adrucil is converted intracellularly to several active metabolites: fluorodeoxyuridine monophosphate (FdUMP), fluorodeoxyuridine triphosphate (FdUTP) and fluorouridine triphosphate (FUTP). The Adrucil metabolite FdUMP binds to the nucleotide-binding site of TS, forming a stable ternary complex with the enzyme and CH2THF, thereby blocking binding of the normal substrate dUMP and inhibiting dTMP synthesis. Metabolite of Adrucil also can be misincorporated into DNA, leading to DNA strand breaks and cell death. The pro-apoptosis effects of Adrucil may be related to its activation of tumor suppressor p53. Loss of p53 function reduces cellular sensitivity to Adrucil.  Adrucil is able to inhibit the survival and induce apoptosis of a board range of cancer cells. Adrucil suppresses viabilities of the nasopharyngeal carcinoma cell line CNE2 and HONE1  , pancreatic cancer cell lines Capan-1  , and human colon carcinoma cell line HT-29  with IC50 of 9 μg/mL, 3 μg/mL, μM, μM, respectively.
Francis Bacon, Philosopher and Writer: Bacon has been a traditional favorite of the anti-Stratford camp, and retains a high place on the list of potential candidates. Bacon proponents point toward Bacon's learning, his correspondences and memoirs (most notably, his notebook, Promus ), as well as ciphers and other coincidences. Although Bacon was an undisputed man of letters, his style and expression vary greatly from that of Shakespeare's works. Bacon also produced such a voluminous output of his own, it's hard to conceive of him finding spare time enough to produce the quality output of work attributed to the Bard.