After sequencing some DNA of pollen and dust found on the shroud, they confirmed that many people from many different places came in contact with the shroud.

How was the shroud of Turin tested?

Using instruments such a ballistic angle finder, the study showed that the direction and behavior of the rivulets of blood did not match those evidenced in high-resolution photographs of the shroud. The cloth is housed in a special case in the Turin Cathedral and goes on display only on rare occasions.

Is the Holy Grail the bloodline of Jesus?

In Browns novel, the protagonist discovers that the grail actually referred to Mary Magdalene, and that knowledge of this, as well as of the bloodline descended from Jesus and Mary, has been kept hidden to the present time by a secret conspiracy.