Cytosine is the "C" of the four bases that make up DNA. Cytosine always pairs with guanine. The other bases are adenine (A), guanine (G), and thymine (T).

Convergence is the process of two genetically distant haplotypes changing over time to resemble one another.

Complementary sequences are opposing strands of DNA. They bond together to form the double helix. The bases always complement one another. Adenine and thymine pair together. Cytosine and guanine pair together.

The CODIS system uses marker locations in the autosomal DNA. In the United States, the FBI maintains a CODIS test result database to identify people and solve crimes.

Cohen is the Hebrew word for priest, which refers to a direct male descendant of Aaron, the brother of Moses. The plural is Cohanim.

The Cohanim Modal Haplotype (CMH) is the Y-chromosome (paternal) profile most frequently found in men with an oral tradition of Cohen ancestry. It is a Y-chromosome DNA STR (Short Tandem Repeat) haplotype.