FKLF2, PCAF, and Sp3 binding at HS2 and HS3. Chromosome DNA was precipitated by antibodies against FKLF2, PCAF, and Sp3. Input DNA or DNA immunoprecipitated by FKLF2, PCAF, and Sp3 antibodies was amplified for 33 cycles in 25 μl of reaction by using pairs of the primers in Table 1.