KLK4 and dental caries: In the group with permanent dentition, the haplotype GAGA in KLK4 (rs198968/rs2978642/rs2242670/rs2235091) was more common in children with dental caries (especially in children with DMFT ≥ 6) than in caries-free children (45.3% vs. 36.5%, p = 0.001, OR = 1.568, 95% CI = 1.200–2.048); on the other hand, the GAGG haplotype seems to be protective against dental caries (p = 0.003, OR = 0.288, 95% CI = 0.130–0.639, Table 4).