Desire and selfish tendencies
With desire all other egoistic tendencies develop that are nothing more than modifications and extension of desire itself.
The greed for example is to want more and more of what we want, e.g. more money, more pleasure, more fame, etc. Gluttony is a desire and greed for more and more pleasure through eating, similarly lasciviousness is a desire and greed for more and more sexual pleasure. Ambition is a desire for fama o glory and it is also a greed for more and more glory, avarice is a desire for money and it is also greed for more and more money. Desire is transformed into jealousy because others have what we want, desire is transformed into anger when something or someone impedes the fulfilment of our desire, desire transforms into fear because we may not get or may lose what we desire, etc.. All the branches of the ego tree (selfish tendencies and inferior emotions) are basically modifications of desire.
Since desire is the root cause of our selfish tendencies and misery, it means that our freedom and happiness are acquired by the dissolution of desire.
"Out of desire comes suffering, out of desire fear. For one who is free from desire, there is neither suffering nor fear."
~ Buddha