Discovery of a Novel Murine Keratin 6 (K6) Isoform Explains the Absence of Hair and Nail Defects in Mice Deficient for K6a and K6b

Researchers discovered a novel murine keratin 6 isoform, MK6hf, which explained why mice deficient in the known keratin 6 genes, MK6a and MK6b, did not exhibit hair and nail defects. Although most MK6a/b−/− mice died early due to tongue epithelium issues, about 25% survived to adulthood with normal hair and nails. The presence of MK6hf in hair follicles and nail beds of these mice suggested it compensated for the absence of MK6a and MK6b, as it is homologous to human K6hf, known for its expression in hair follicles.