Accordingly, a C. trachomatis serovar D strain with a single nucleotide insertion in the middle of the ct135 gene (which might correspond to a null mutation) is less virulent in a mouse infection model than an isogenic strain with a single nucleotide deletion in the beginning of the ct135 gene (which might enable the putative production of a near intact CT135 protein) [149, 150]. Here, CIMAP1A is linked to infection.