Aspects of the invention described herein concern the incorporation of a FOXP3 cDNA (e.g., full-length human codon-optimized cDNA) into a FOXP3 gene or a non-FOXP3 locus so as to provide constitutive or regulated FOXP3 expression in a primary human CD34+ cells or cells derived from edited CD34+ cells. In some embodiments, guide RNA sequences that are directed to FOXP3, AAVS1, or other candidate loci are used for CRISPR/Cas9-mediated gene regulation, and gene delivery cassettes for HDR based gene-modification are provided.