Many have related the Mona Lisa to the so called "Jesus Theory." This revealing of this conspiracy could lead to the downfall of the Church itself. The content of this secret is that Jesus had a female partner during his mortal life on Earth. This secret could be seen in a number of paintings, especially the Last Supper. A woman holding a baby sits on the right hand of the Son of the Lord, while one of Jesus' disciples - Peter - is leaning menacingly towards the woman. Leaving aside the Last Supper, the Sistine Chapel could be a perfect proof for this conspiracy. Notice a woman next to Jesus Christ, in the scene of Judgement Day. Why had not the Pope blame Michelangelo for that, since the period of the Inquisition was closing up?

( Notice the woman next to Jesus Christ.)
Leonardo da Vinci's mischievous side can be seen inside the Last Supper. Therefore, there should be no doubt that the Mona Lisa's smile makes reference to the Jesus Theory.