PROS1 and in situ carcinoma: To identify the putative CIS-associated effector protein(s), we constructed a strain expressing CISs tagged with hexahistidine at the PAAR-repeat protein-like BN159_7582 (Tip) which is predicted to be a needle tip-like protein that forms a complex with a VgrG-like spike protein (Figs. 1a and 3a).24,25 A strain expressing a non-tagged Tip was also constructed as a control.