You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Ghon’s focus is found in and explain in detail?
Ghon’s focus

In primary tuberculosis when inhaled tubercule bacilli implanted in the distal air spaces of the lower part of an upper lobe or upper part of the lower lobe, close to the pleura. This area is about 1 to 1.5 cm with caseating necrosis known as Ghon’s focus.
Ghon’s focus is one of the components of Ghon’s complex (primary complex), which consists of 3 components: -

i) Ghon’s focus (subpleural caseating lesion)
ii) Caseating hilar lymph node
iii) Draining lymphatics. 
Note - Due to early bacteremia (bacillemia) seeding of tubercle bacilli may occur at the apex to produce Simon’s focus.