Using the sequence of the SP1 zinc-finger DNA-binding domain as a probe to screen a mouse EST database, we identified two novel members of the SP/XKLF transcription factor family, KLF13 and KLF14. The mouse Klf13 cDNA (1310 bp in length) contains a single open reading frame of 288 amino acids with a DNA-binding domain closely related to that of the human RFLAT-1 protein and a putative transactivator N-terminal domain rich in proline and alanine residues. The mouse Klf13 gene seems to be the homologue of the human RFLAT1 gene. The mouse Klf14 sequence is homologous to a human genomic sequence from chromosome 17 that is believed to code for a protein with three zinc fingers at the end of its C-terminal domain. Using reverse transcription–polymerase chain reaction, we showed ubiquitous expression of Klf13 and Klf14 in adult mice. A third member of this family was also identified in a human EST database; this sequence was found to be identical to KLF11 (TIEG2), recently identified by Cook et al. (1998, J. Biol. Chem. 273: 25929–25936). The corresponding mouse cDNA was isolated and sequenced. The three genes were localized in the human and the rat: chromosomes 15 (human KLF13), 17q21.3–q22 (human KLF14; HGMW-approved symbol SP6), and 2p25 (human KLF11) and chromosomes 1q31–q32 (rat Klf13), 10q31–q32.1 (rat Klf14) (SP6), and 6q16–q21 (rat Klf11).