Because there is no effect of sealing wax, the pen can only be stored for a few months. Without sealing wax, it will be oxidized by some substances in the air. The top of the pen ink is sealed with oil. After a long time, the sealing oil molecules will move with the ink molecules of gel pen, so the sealing wax on the refill can be kept for several months.
Gel pens, like most things, can be placed in a dry and cool place.