[1] He missed Athens 2004 and Beijing 2008 but in London 2012, he won a bronze medal in boccia for mixed pairs BC3.

[1] Cilissen also competed in the 2016 Summer Paralympics in Rio de Janeiro but failed to get a medal.

[2] Due to an oxygen defect at birth, Cilissen suffers from cerebral palsy, which leaves him incapable of controlling the movement of arms and legs and impediments his speech.

[3] At the 2010 Boccia World Championships in Lisbon, he won a bronze medal in the Pairs BCS together with Kirsten De Laender and Pieter Verlinden.

[1] At the 2012 Summer Paralympics, in London, he won a bronze medal in Pairs BC3, with Kirsten De Laender and Pieter Verlinden.