List the following steps of phagocytosis in order: adhesion, chemotaxis, engulfment, phagosome formation, phagolysosome formation, killing, residual body. Which step comes first in the process of phagocytosis?
1) Adhesion
2) Chemotaxis
3) Engulfment
4) Phagosome formation
5) Phagolysosome formation
6) Killing
7) Residual body