mysql - SQL Query for Where IN condition -

i having situation this

select *  user_post  user_id in (select user_id follow follow_id=20) 

this query working fine, need add follow_id 20 in condition... selected user_id plus user 20 included in in condition

i tried this

select *  user_post  user_id in (select user_id follow follow_id=20) , user_id=20 

it did not bring proper result

the query should this

select *  user_post  user_id in (10,15,20)  

how this

select     *       user_post      user_id in ((select                      follow_id                                       follow                                       follow_id=20), 10, 15);