We have reported transgenic mice expressing tva from the promoter of MMTV (MMTV-tva) for indiscriminate infection of the luminal epithelium [13], and from the promoters of WAP, TOP, and Krt6a [7,14–16] for selective infection of WAP+, canonical Wnt signaling-active, and Krt6a+ cells, respectively. This evidence concerns the gene KRT6A and infection.