Removable catheter cap, and applications thereof, for delivering medical tubes in bodily passages. Removable catheter cap covers flexible medical tube (e.g., catheter) distal tip during delivery in a body lumen. Catheter cap includes: cap body removably connectable to, for capping, catheter distal tip, and transformable into a predefined constituent part freely passable through catheter lumen and cap releasing member extending through catheter proximal end when catheter cap is connected to the catheter, and manipulatable for transforming cap body into constituent part or/and for withdrawing constituent part from catheter distal tip through catheter lumen. Exemplary applications are: provision of a catheter assembly including a catheter and the removable catheter cap connected thereto a medical kit including one or more catheters and one or more correspondingly configured removable catheter caps and a method for delivering a catheter in a blood vessel of a subject, for example, via an over-the-wire technique.