Bello's final appearance as Dr. Jacqueline "Jack" Sloane aired Tuesday night after three seasons. "And that's a wrap for Jack Sloane @ncis_cbs !!!" she wrote on Instagram. "I've learned many things on this journey for the last three and a half years. I learned about commitment and community. I've learned that the woman I am enjoys process over product. I've never worked with a kinder, more generous group of people. I only had the privilege of standing by Dom's side during cancer because my producers worked so hard to make sure I was there for every treatment. I made a speech today for our crew. Though in our business, like many, there are quite a few a**holes - there is not one on the set of NCIS - in front of or behind the camera. Only a profoundly decent group of people who care more about each other and the world in general than what is in it for them. I understand why this show after 18 years is the most watched in the world - you must all feel our love. Keep watching. I have a feeling there will be many more years to come. Thank you to all of my pals at NCIS and to all of our fans. I am truly grateful."