Fetal Hemoglobin Quantitative Trait Locus 6, also known as hereditary persistence of fetal hemoglobin, klf1-related, is related to fetal hemoglobin quantitative trait locus 1 and hereditary persistence of fetal hemoglobin-beta-thalassemia syndrome. An important gene associated with Fetal Hemoglobin Quantitative Trait Locus 6 is KLF1 (KLF Transcription Factor 1). Affiliated tissues include bone marrow and spleen.